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I want to calculate the circumstance of the Sun around the Galaxy; the Math Formula is ((241828072282107.5071453596951 * 666) * 2) * 3.14159265359, using QML JavaScript I get the answer 1011954093357316100, when the correct answer is 1011954093357316200, a 100 miles off.
galaxyRadius="241828072282107.5071453596951";
currentTrackNumber=666; // Track Number like on a Record
pIe="3.14159265359"; // not the same as Math.PI
I had to use strings because converting these sized numbers to floats truncate the precision, I am converting an old bash script, and it worked fine with bc, not so much Math.
I have tried this:
orbitDist = ((( Number.parseFloat(galaxyRadius).toPrecision(20) * currentTrackNumber) * 2) * Number.parseFloat(pIe).toPrecision(12) );
I get the same results as:
orbitDist = ((( galaxyRadius * currentTrackNumber) * 2) * pIe );
from bash:
echo "$(bc <<< "scale=13;((241828072282107.5071453596951 * 666) * 2) * 3.14159265359")"
Bash is right and JavaScript is wrong by almost a 100 miles, that is crazy, it is freaking me out, how can JavaScript Floating Point Math be so far off, and this is just one example, I have a whole app full of numbers that are close, but not even close enough, a 100 miles off is not acceptable.
I do not want to deal with exponents, I want the value as an Integer, Strings are fine, it is stored in a database as string, I just need the Math to be right.
This is a QtQuick, QML, Felgo App, using Qml and JavaScript, so it will need to run on different platforms. My next thought is C++, or a Math Library that works for this type of project, JavaScript or a QML wrapper Library for C++ would be great, figuring out how make JavaScript not so bad at Floating Point would be better, I found a few JavaScript Libraries for the Web, they do not work without a lot of work under Qml, so I am only interested in what works, and I did a lot of research and did not find what I was looking for.
javascript bash qt math qml
edited Mar 29 at 3:30
eyllanesc
104k12 gold badges38 silver badges70 bronze badges
asked Mar 27 at 0:51
user83395user83395
481 silver badge5 bronze badges
add a comment |
I want to calculate the circumstance of the Sun around the Galaxy; the Math Formula is ((241828072282107.5071453596951 * 666) * 2) * 3.14159265359, using QML JavaScript I get the answer 1011954093357316100, when the correct answer is 1011954093357316200, a 100 miles off.
galaxyRadius="241828072282107.5071453596951";
currentTrackNumber=666; // Track Number like on a Record
pIe="3.14159265359"; // not the same as Math.PI
I had to use strings because converting these sized numbers to floats truncate the precision, I am converting an old bash script, and it worked fine with bc, not so much Math.
I have tried this:
orbitDist = ((( Number.parseFloat(galaxyRadius).toPrecision(20) * currentTrackNumber) * 2) * Number.parseFloat(pIe).toPrecision(12) );
I get the same results as:
orbitDist = ((( galaxyRadius * currentTrackNumber) * 2) * pIe );
from bash:
echo "$(bc <<< "scale=13;((241828072282107.5071453596951 * 666) * 2) * 3.14159265359")"
Bash is right and JavaScript is wrong by almost a 100 miles, that is crazy, it is freaking me out, how can JavaScript Floating Point Math be so far off, and this is just one example, I have a whole app full of numbers that are close, but not even close enough, a 100 miles off is not acceptable.
I do not want to deal with exponents, I want the value as an Integer, Strings are fine, it is stored in a database as string, I just need the Math to be right.
This is a QtQuick, QML, Felgo App, using Qml and JavaScript, so it will need to run on different platforms. My next thought is C++, or a Math Library that works for this type of project, JavaScript or a QML wrapper Library for C++ would be great, figuring out how make JavaScript not so bad at Floating Point would be better, I found a few JavaScript Libraries for the Web, they do not work without a lot of work under Qml, so I am only interested in what works, and I did a lot of research and did not find what I was looking for.
javascript bash qt math qml
edited Mar 29 at 3:30
eyllanesc
104k12 gold badges38 silver badges70 bronze badges
asked Mar 27 at 0:51
user83395user83395
481 silver badge5 bronze badges
1
JavaScript precision just isn't good enough for your extremely large numbers. I assumed you looked into the various big* libraries that would solve the precision issue? (github.com/MikeMcl).
– Cᴏʀʏ
Mar 27 at 0:57
I was referring to this one above, it was not written for Qml JavaScript, it would take a lot of work to get it to just have no error or warnings, I started by removing "use strict", and changing the == to === and so on, but run into problems with variables not being defined before use, and fixing some of them, lead to more problems, it can be converted, never done that before, was hoping for a library that made for Qml.
– user83395
Mar 27 at 1:32
@user83395 In SO you should not add SOLVED to the title of the question, instead you should mark the question that helped you solve your problem, if instead you found the solution then we invite you to publish a solution and mark it as correct in 2 days , for more information check the tour :-)
– eyllanesc
Mar 29 at 3:32
add a comment |
I want to calculate the circumstance of the Sun around the Galaxy; the Math Formula is ((241828072282107.5071453596951 * 666) * 2) * 3.14159265359, using QML JavaScript I get the answer 1011954093357316100, when the correct answer is 1011954093357316200, a 100 miles off.
galaxyRadius="241828072282107.5071453596951";
currentTrackNumber=666; // Track Number like on a Record
pIe="3.14159265359"; // not the same as Math.PI
I had to use strings because converting these sized numbers to floats truncate the precision, I am converting an old bash script, and it worked fine with bc, not so much Math.
I have tried this:
orbitDist = ((( Number.parseFloat(galaxyRadius).toPrecision(20) * currentTrackNumber) * 2) * Number.parseFloat(pIe).toPrecision(12) );
I get the same results as:
orbitDist = ((( galaxyRadius * currentTrackNumber) * 2) * pIe );
from bash:
echo "$(bc <<< "scale=13;((241828072282107.5071453596951 * 666) * 2) * 3.14159265359")"
Bash is right and JavaScript is wrong by almost a 100 miles, that is crazy, it is freaking me out, how can JavaScript Floating Point Math be so far off, and this is just one example, I have a whole app full of numbers that are close, but not even close enough, a 100 miles off is not acceptable.
I do not want to deal with exponents, I want the value as an Integer, Strings are fine, it is stored in a database as string, I just need the Math to be right.
This is a QtQuick, QML, Felgo App, using Qml and JavaScript, so it will need to run on different platforms. My next thought is C++, or a Math Library that works for this type of project, JavaScript or a QML wrapper Library for C++ would be great, figuring out how make JavaScript not so bad at Floating Point would be better, I found a few JavaScript Libraries for the Web, they do not work without a lot of work under Qml, so I am only interested in what works, and I did a lot of research and did not find what I was looking for.
javascript bash qt math qml
edited Mar 29 at 3:30
eyllanesc
104k12 gold badges38 silver badges70 bronze badges
asked Mar 27 at 0:51
user83395user83395
481 silver badge5 bronze badges
I want to calculate the circumstance of the Sun around the Galaxy; the Math Formula is ((241828072282107.5071453596951 * 666) * 2) * 3.14159265359, using QML JavaScript I get the answer 1011954093357316100, when the correct answer is 1011954093357316200, a 100 miles off.
galaxyRadius="241828072282107.5071453596951";
currentTrackNumber=666; // Track Number like on a Record
pIe="3.14159265359"; // not the same as Math.PI
I had to use strings because converting these sized numbers to floats truncate the precision, I am converting an old bash script, and it worked fine with bc, not so much Math.
I have tried this:
orbitDist = ((( Number.parseFloat(galaxyRadius).toPrecision(20) * currentTrackNumber) * 2) * Number.parseFloat(pIe).toPrecision(12) );
I get the same results as:
orbitDist = ((( galaxyRadius * currentTrackNumber) * 2) * pIe );
from bash:
echo "$(bc <<< "scale=13;((241828072282107.5071453596951 * 666) * 2) * 3.14159265359")"
Bash is right and JavaScript is wrong by almost a 100 miles, that is crazy, it is freaking me out, how can JavaScript Floating Point Math be so far off, and this is just one example, I have a whole app full of numbers that are close, but not even close enough, a 100 miles off is not acceptable.
I do not want to deal with exponents, I want the value as an Integer, Strings are fine, it is stored in a database as string, I just need the Math to be right.
This is a QtQuick, QML, Felgo App, using Qml and JavaScript, so it will need to run on different platforms. My next thought is C++, or a Math Library that works for this type of project, JavaScript or a QML wrapper Library for C++ would be great, figuring out how make JavaScript not so bad at Floating Point would be better, I found a few JavaScript Libraries for the Web, they do not work without a lot of work under Qml, so I am only interested in what works, and I did a lot of research and did not find what I was looking for.
javascript bash qt math qml
javascript bash qt math qml
edited Mar 29 at 3:30
eyllanesc
104k12 gold badges38 silver badges70 bronze badges
asked Mar 27 at 0:51
user83395user83395
481 silver badge5 bronze badges
edited Mar 29 at 3:30
eyllanesc
104k12 gold badges38 silver badges70 bronze badges
asked Mar 27 at 0:51
user83395user83395
481 silver badge5 bronze badges
edited Mar 29 at 3:30
eyllanesc
104k12 gold badges38 silver badges70 bronze badges
edited Mar 29 at 3:30
eyllanesc
104k12 gold badges38 silver badges70 bronze badges
edited Mar 29 at 3:30
eyllanesc
104k12 gold badges38 silver badges70 bronze badges
104k12 gold badges38 silver badges70 bronze badges
asked Mar 27 at 0:51
user83395user83395
481 silver badge5 bronze badges
asked Mar 27 at 0:51
user83395user83395
481 silver badge5 bronze badges
asked Mar 27 at 0:51
user83395user83395
481 silver badge5 bronze badges
481 silver badge5 bronze badges
1
JavaScript precision just isn't good enough for your extremely large numbers. I assumed you looked into the various big* libraries that would solve the precision issue? (github.com/MikeMcl).
– Cᴏʀʏ
Mar 27 at 0:57
I was referring to this one above, it was not written for Qml JavaScript, it would take a lot of work to get it to just have no error or warnings, I started by removing "use strict", and changing the == to === and so on, but run into problems with variables not being defined before use, and fixing some of them, lead to more problems, it can be converted, never done that before, was hoping for a library that made for Qml.
– user83395
Mar 27 at 1:32
@user83395 In SO you should not add SOLVED to the title of the question, instead you should mark the question that helped you solve your problem, if instead you found the solution then we invite you to publish a solution and mark it as correct in 2 days , for more information check the tour :-)
– eyllanesc
Mar 29 at 3:32
add a comment |
1
JavaScript precision just isn't good enough for your extremely large numbers. I assumed you looked into the various big* libraries that would solve the precision issue? (github.com/MikeMcl).
– Cᴏʀʏ
Mar 27 at 0:57
I was referring to this one above, it was not written for Qml JavaScript, it would take a lot of work to get it to just have no error or warnings, I started by removing "use strict", and changing the == to === and so on, but run into problems with variables not being defined before use, and fixing some of them, lead to more problems, it can be converted, never done that before, was hoping for a library that made for Qml.
– user83395
Mar 27 at 1:32
@user83395 In SO you should not add SOLVED to the title of the question, instead you should mark the question that helped you solve your problem, if instead you found the solution then we invite you to publish a solution and mark it as correct in 2 days , for more information check the tour :-)
– eyllanesc
Mar 29 at 3:32
1
1
JavaScript precision just isn't good enough for your extremely large numbers. I assumed you looked into the various big* libraries that would solve the precision issue? (github.com/MikeMcl).
– Cᴏʀʏ
Mar 27 at 0:57
JavaScript precision just isn't good enough for your extremely large numbers. I assumed you looked into the various big* libraries that would solve the precision issue? (github.com/MikeMcl).
– Cᴏʀʏ
Mar 27 at 0:57
I was referring to this one above, it was not written for Qml JavaScript, it would take a lot of work to get it to just have no error or warnings, I started by removing "use strict", and changing the == to === and so on, but run into problems with variables not being defined before use, and fixing some of them, lead to more problems, it can be converted, never done that before, was hoping for a library that made for Qml.
– user83395
Mar 27 at 1:32
I was referring to this one above, it was not written for Qml JavaScript, it would take a lot of work to get it to just have no error or warnings, I started by removing "use strict", and changing the == to === and so on, but run into problems with variables not being defined before use, and fixing some of them, lead to more problems, it can be converted, never done that before, was hoping for a library that made for Qml.
– user83395
Mar 27 at 1:32
@user83395 In SO you should not add SOLVED to the title of the question, instead you should mark the question that helped you solve your problem, if instead you found the solution then we invite you to publish a solution and mark it as correct in 2 days , for more information check the tour :-)
– eyllanesc
Mar 29 at 3:32
@user83395 In SO you should not add SOLVED to the title of the question, instead you should mark the question that helped you solve your problem, if instead you found the solution then we invite you to publish a solution and mark it as correct in 2 days , for more information check the tour :-)
– eyllanesc
Mar 29 at 3:32
add a comment |
1 Answer
1
active
oldest
votes
Because of JavaScript for now just support bignum for integer(BigInt) only. Then I convert it to BigInt before calculate. And tracking the decimal part to re-convert to float.
const galaxyRadius="241828072282107.5071453596951";
const currentTrackNumber=666; // Track Number like on a Record
const pIe="3.14159265359"; // not the same as Math.PI
const orbitDist = ((( galaxyRadius * currentTrackNumber) * 2) * pIe );
console.log(orbitDist)
//// My approad
//Put all number into an array
var arrToMul = [galaxyRadius,currentTrackNumber, 2, pIe]
// Function multiple all item in array with BigInt format
function mulBigInt(arr)
return arr.reduce(function (acc, e)
return BigInt(e) * acc;
, BigInt(1));
;
// Function get length of decimal part
function decLength(str)
var dec = str.toString().split('.')[1];
return dec ? dec.length : 0;
;
// Function remove point in string to convert float to int
function rmPoint(strNum)
return strNum.toString().replace('.', "");
;
// Main function
function cal(arr)
// Get total decimal part length of all number
var pointSize = arr.reduce(function (acc, e)
return acc + decLength(e);
, 0);
// convert the all item to int (type string)
var newArr = arr.map(function (e)
return rmPoint(e);
);
// Add point to reconvert BigInt to float(string acctually)
var tmp = mulBigInt(newArr).toString().split('');
tmp.splice(tmp.length - pointSize, 0, '.');
// Return float result with string format
return tmp.join('');
;
const rs = cal(arrToMul)
console.log(rs, 'converted to BigInt:')answered Mar 27 at 2:11
birdbird
1,3239 silver badges20 bronze badges
QtCreator Qml JavaScript is choking on the arrow function expression, I will have to figure out how to convert them to a regular function call, unless you can update your answer to work in QtCreator, never used arrow function, I do see from researching them that they do not work in Qml, but no idea how to convert right now, will look into it, the answer is right, so it is just a matter of getting it work in Qml. Thanks, great work, did not know about this, was working on a C++ solution, like this better, a lot more precision. bugreports.qt.io/browse/QTBUG-47735
– user83395
Mar 27 at 4:53
@user83395 I updated the answer to convert arrow function into normal function. Hope it help.
– bird
Mar 27 at 5:27
Thanks, close, just add new in front of BigInt, some warning about using new before functions that start with capital letters, then I get a BigInt undefined error, looking at developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/…, it seems this is built in, google did not help find a solution, Qml JavaScript is just not the same as Web, do you know if I need to import it, if so how? Thanks for all the help, I assume you got this to work using Qt Creator, assume, you know what that means.
– user83395
Mar 27 at 5:52
My efforts in C++ gave me 1011954093357316096, which is worse than JavaScript, seems 64 bits is not enough, and that was using a Double, I will have to look into Arbitrary Precision Math Libraries next, I hope I can use BigInt, google is no help, all I can find is for Web use, not Qml.
– user83395
Mar 27 at 6:14
I figure out one of my problems with using any JavaScript Solution, and that is that anytime you have to do any Math that involves a Float, or you have to convert to a float for any reason, you are going to have precision issues, BigInt that bird showed, works great, but I could not figure out how to use it in Qml, Qt states to look for JavaScript Examples, when most do not work, BigInt is one, plus there is a "this" bug to deal with, so I switched to boost math multiprecision, I have one issue with it, another thread, but it does give me the correct answer, so thanks for all the help.
– user83395
Mar 29 at 1:02
add a comment |
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1 Answer
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1 Answer
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active
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active
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votes
Because of JavaScript for now just support bignum for integer(BigInt) only. Then I convert it to BigInt before calculate. And tracking the decimal part to re-convert to float.
const galaxyRadius="241828072282107.5071453596951";
const currentTrackNumber=666; // Track Number like on a Record
const pIe="3.14159265359"; // not the same as Math.PI
const orbitDist = ((( galaxyRadius * currentTrackNumber) * 2) * pIe );
console.log(orbitDist)
//// My approad
//Put all number into an array
var arrToMul = [galaxyRadius,currentTrackNumber, 2, pIe]
// Function multiple all item in array with BigInt format
function mulBigInt(arr)
return arr.reduce(function (acc, e)
return BigInt(e) * acc;
, BigInt(1));
;
// Function get length of decimal part
function decLength(str)
var dec = str.toString().split('.')[1];
return dec ? dec.length : 0;
;
// Function remove point in string to convert float to int
function rmPoint(strNum)
return strNum.toString().replace('.', "");
;
// Main function
function cal(arr)
// Get total decimal part length of all number
var pointSize = arr.reduce(function (acc, e)
return acc + decLength(e);
, 0);
// convert the all item to int (type string)
var newArr = arr.map(function (e)
return rmPoint(e);
);
// Add point to reconvert BigInt to float(string acctually)
var tmp = mulBigInt(newArr).toString().split('');
tmp.splice(tmp.length - pointSize, 0, '.');
// Return float result with string format
return tmp.join('');
;
const rs = cal(arrToMul)
console.log(rs, 'converted to BigInt:')answered Mar 27 at 2:11
birdbird
1,3239 silver badges20 bronze badges
QtCreator Qml JavaScript is choking on the arrow function expression, I will have to figure out how to convert them to a regular function call, unless you can update your answer to work in QtCreator, never used arrow function, I do see from researching them that they do not work in Qml, but no idea how to convert right now, will look into it, the answer is right, so it is just a matter of getting it work in Qml. Thanks, great work, did not know about this, was working on a C++ solution, like this better, a lot more precision. bugreports.qt.io/browse/QTBUG-47735
– user83395
Mar 27 at 4:53
@user83395 I updated the answer to convert arrow function into normal function. Hope it help.
– bird
Mar 27 at 5:27
Thanks, close, just add new in front of BigInt, some warning about using new before functions that start with capital letters, then I get a BigInt undefined error, looking at developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/…, it seems this is built in, google did not help find a solution, Qml JavaScript is just not the same as Web, do you know if I need to import it, if so how? Thanks for all the help, I assume you got this to work using Qt Creator, assume, you know what that means.
– user83395
Mar 27 at 5:52
My efforts in C++ gave me 1011954093357316096, which is worse than JavaScript, seems 64 bits is not enough, and that was using a Double, I will have to look into Arbitrary Precision Math Libraries next, I hope I can use BigInt, google is no help, all I can find is for Web use, not Qml.
– user83395
Mar 27 at 6:14
I figure out one of my problems with using any JavaScript Solution, and that is that anytime you have to do any Math that involves a Float, or you have to convert to a float for any reason, you are going to have precision issues, BigInt that bird showed, works great, but I could not figure out how to use it in Qml, Qt states to look for JavaScript Examples, when most do not work, BigInt is one, plus there is a "this" bug to deal with, so I switched to boost math multiprecision, I have one issue with it, another thread, but it does give me the correct answer, so thanks for all the help.
– user83395
Mar 29 at 1:02
add a comment |
Because of JavaScript for now just support bignum for integer(BigInt) only. Then I convert it to BigInt before calculate. And tracking the decimal part to re-convert to float.
const galaxyRadius="241828072282107.5071453596951";
const currentTrackNumber=666; // Track Number like on a Record
const pIe="3.14159265359"; // not the same as Math.PI
const orbitDist = ((( galaxyRadius * currentTrackNumber) * 2) * pIe );
console.log(orbitDist)
//// My approad
//Put all number into an array
var arrToMul = [galaxyRadius,currentTrackNumber, 2, pIe]
// Function multiple all item in array with BigInt format
function mulBigInt(arr)
return arr.reduce(function (acc, e)
return BigInt(e) * acc;
, BigInt(1));
;
// Function get length of decimal part
function decLength(str)
var dec = str.toString().split('.')[1];
return dec ? dec.length : 0;
;
// Function remove point in string to convert float to int
function rmPoint(strNum)
return strNum.toString().replace('.', "");
;
// Main function
function cal(arr)
// Get total decimal part length of all number
var pointSize = arr.reduce(function (acc, e)
return acc + decLength(e);
, 0);
// convert the all item to int (type string)
var newArr = arr.map(function (e)
return rmPoint(e);
);
// Add point to reconvert BigInt to float(string acctually)
var tmp = mulBigInt(newArr).toString().split('');
tmp.splice(tmp.length - pointSize, 0, '.');
// Return float result with string format
return tmp.join('');
;
const rs = cal(arrToMul)
console.log(rs, 'converted to BigInt:')answered Mar 27 at 2:11
birdbird
1,3239 silver badges20 bronze badges
QtCreator Qml JavaScript is choking on the arrow function expression, I will have to figure out how to convert them to a regular function call, unless you can update your answer to work in QtCreator, never used arrow function, I do see from researching them that they do not work in Qml, but no idea how to convert right now, will look into it, the answer is right, so it is just a matter of getting it work in Qml. Thanks, great work, did not know about this, was working on a C++ solution, like this better, a lot more precision. bugreports.qt.io/browse/QTBUG-47735
– user83395
Mar 27 at 4:53
@user83395 I updated the answer to convert arrow function into normal function. Hope it help.
– bird
Mar 27 at 5:27
Thanks, close, just add new in front of BigInt, some warning about using new before functions that start with capital letters, then I get a BigInt undefined error, looking at developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/…, it seems this is built in, google did not help find a solution, Qml JavaScript is just not the same as Web, do you know if I need to import it, if so how? Thanks for all the help, I assume you got this to work using Qt Creator, assume, you know what that means.
– user83395
Mar 27 at 5:52
My efforts in C++ gave me 1011954093357316096, which is worse than JavaScript, seems 64 bits is not enough, and that was using a Double, I will have to look into Arbitrary Precision Math Libraries next, I hope I can use BigInt, google is no help, all I can find is for Web use, not Qml.
– user83395
Mar 27 at 6:14
I figure out one of my problems with using any JavaScript Solution, and that is that anytime you have to do any Math that involves a Float, or you have to convert to a float for any reason, you are going to have precision issues, BigInt that bird showed, works great, but I could not figure out how to use it in Qml, Qt states to look for JavaScript Examples, when most do not work, BigInt is one, plus there is a "this" bug to deal with, so I switched to boost math multiprecision, I have one issue with it, another thread, but it does give me the correct answer, so thanks for all the help.
– user83395
Mar 29 at 1:02
add a comment |
Because of JavaScript for now just support bignum for integer(BigInt) only. Then I convert it to BigInt before calculate. And tracking the decimal part to re-convert to float.
const galaxyRadius="241828072282107.5071453596951";
const currentTrackNumber=666; // Track Number like on a Record
const pIe="3.14159265359"; // not the same as Math.PI
const orbitDist = ((( galaxyRadius * currentTrackNumber) * 2) * pIe );
console.log(orbitDist)
//// My approad
//Put all number into an array
var arrToMul = [galaxyRadius,currentTrackNumber, 2, pIe]
// Function multiple all item in array with BigInt format
function mulBigInt(arr)
return arr.reduce(function (acc, e)
return BigInt(e) * acc;
, BigInt(1));
;
// Function get length of decimal part
function decLength(str)
var dec = str.toString().split('.')[1];
return dec ? dec.length : 0;
;
// Function remove point in string to convert float to int
function rmPoint(strNum)
return strNum.toString().replace('.', "");
;
// Main function
function cal(arr)
// Get total decimal part length of all number
var pointSize = arr.reduce(function (acc, e)
return acc + decLength(e);
, 0);
// convert the all item to int (type string)
var newArr = arr.map(function (e)
return rmPoint(e);
);
// Add point to reconvert BigInt to float(string acctually)
var tmp = mulBigInt(newArr).toString().split('');
tmp.splice(tmp.length - pointSize, 0, '.');
// Return float result with string format
return tmp.join('');
;
const rs = cal(arrToMul)
console.log(rs, 'converted to BigInt:')answered Mar 27 at 2:11
birdbird
1,3239 silver badges20 bronze badges
Because of JavaScript for now just support bignum for integer(BigInt) only. Then I convert it to BigInt before calculate. And tracking the decimal part to re-convert to float.
const galaxyRadius="241828072282107.5071453596951";
const currentTrackNumber=666; // Track Number like on a Record
const pIe="3.14159265359"; // not the same as Math.PI
const orbitDist = ((( galaxyRadius * currentTrackNumber) * 2) * pIe );
console.log(orbitDist)
//// My approad
//Put all number into an array
var arrToMul = [galaxyRadius,currentTrackNumber, 2, pIe]
// Function multiple all item in array with BigInt format
function mulBigInt(arr)
return arr.reduce(function (acc, e)
return BigInt(e) * acc;
, BigInt(1));
;
// Function get length of decimal part
function decLength(str)
var dec = str.toString().split('.')[1];
return dec ? dec.length : 0;
;
// Function remove point in string to convert float to int
function rmPoint(strNum)
return strNum.toString().replace('.', "");
;
// Main function
function cal(arr)
// Get total decimal part length of all number
var pointSize = arr.reduce(function (acc, e)
return acc + decLength(e);
, 0);
// convert the all item to int (type string)
var newArr = arr.map(function (e)
return rmPoint(e);
);
// Add point to reconvert BigInt to float(string acctually)
var tmp = mulBigInt(newArr).toString().split('');
tmp.splice(tmp.length - pointSize, 0, '.');
// Return float result with string format
return tmp.join('');
;
const rs = cal(arrToMul)
console.log(rs, 'converted to BigInt:')const galaxyRadius="241828072282107.5071453596951";
const currentTrackNumber=666; // Track Number like on a Record
const pIe="3.14159265359"; // not the same as Math.PI
const orbitDist = ((( galaxyRadius * currentTrackNumber) * 2) * pIe );
console.log(orbitDist)
//// My approad
//Put all number into an array
var arrToMul = [galaxyRadius,currentTrackNumber, 2, pIe]
// Function multiple all item in array with BigInt format
function mulBigInt(arr)
return arr.reduce(function (acc, e)
return BigInt(e) * acc;
, BigInt(1));
;
// Function get length of decimal part
function decLength(str)
var dec = str.toString().split('.')[1];
return dec ? dec.length : 0;
;
// Function remove point in string to convert float to int
function rmPoint(strNum)
return strNum.toString().replace('.', "");
;
// Main function
function cal(arr)
// Get total decimal part length of all number
var pointSize = arr.reduce(function (acc, e)
return acc + decLength(e);
, 0);
// convert the all item to int (type string)
var newArr = arr.map(function (e)
return rmPoint(e);
);
// Add point to reconvert BigInt to float(string acctually)
var tmp = mulBigInt(newArr).toString().split('');
tmp.splice(tmp.length - pointSize, 0, '.');
// Return float result with string format
return tmp.join('');
;
const rs = cal(arrToMul)
console.log(rs, 'converted to BigInt:')const galaxyRadius="241828072282107.5071453596951";
const currentTrackNumber=666; // Track Number like on a Record
const pIe="3.14159265359"; // not the same as Math.PI
const orbitDist = ((( galaxyRadius * currentTrackNumber) * 2) * pIe );
console.log(orbitDist)
//// My approad
//Put all number into an array
var arrToMul = [galaxyRadius,currentTrackNumber, 2, pIe]
// Function multiple all item in array with BigInt format
function mulBigInt(arr)
return arr.reduce(function (acc, e)
return BigInt(e) * acc;
, BigInt(1));
;
// Function get length of decimal part
function decLength(str)
var dec = str.toString().split('.')[1];
return dec ? dec.length : 0;
;
// Function remove point in string to convert float to int
function rmPoint(strNum)
return strNum.toString().replace('.', "");
;
// Main function
function cal(arr)
// Get total decimal part length of all number
var pointSize = arr.reduce(function (acc, e)
return acc + decLength(e);
, 0);
// convert the all item to int (type string)
var newArr = arr.map(function (e)
return rmPoint(e);
);
// Add point to reconvert BigInt to float(string acctually)
var tmp = mulBigInt(newArr).toString().split('');
tmp.splice(tmp.length - pointSize, 0, '.');
// Return float result with string format
return tmp.join('');
;
const rs = cal(arrToMul)
console.log(rs, 'converted to BigInt:')answered Mar 27 at 2:11
birdbird
1,3239 silver badges20 bronze badges
edited Mar 27 at 5:26
answered Mar 27 at 2:11
birdbird
1,3239 silver badges20 bronze badges
answered Mar 27 at 2:11
birdbird
1,3239 silver badges20 bronze badges
answered Mar 27 at 2:11
birdbird
1,3239 silver badges20 bronze badges
1,3239 silver badges20 bronze badges
QtCreator Qml JavaScript is choking on the arrow function expression, I will have to figure out how to convert them to a regular function call, unless you can update your answer to work in QtCreator, never used arrow function, I do see from researching them that they do not work in Qml, but no idea how to convert right now, will look into it, the answer is right, so it is just a matter of getting it work in Qml. Thanks, great work, did not know about this, was working on a C++ solution, like this better, a lot more precision. bugreports.qt.io/browse/QTBUG-47735
– user83395
Mar 27 at 4:53
@user83395 I updated the answer to convert arrow function into normal function. Hope it help.
– bird
Mar 27 at 5:27
Thanks, close, just add new in front of BigInt, some warning about using new before functions that start with capital letters, then I get a BigInt undefined error, looking at developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/…, it seems this is built in, google did not help find a solution, Qml JavaScript is just not the same as Web, do you know if I need to import it, if so how? Thanks for all the help, I assume you got this to work using Qt Creator, assume, you know what that means.
– user83395
Mar 27 at 5:52
My efforts in C++ gave me 1011954093357316096, which is worse than JavaScript, seems 64 bits is not enough, and that was using a Double, I will have to look into Arbitrary Precision Math Libraries next, I hope I can use BigInt, google is no help, all I can find is for Web use, not Qml.
– user83395
Mar 27 at 6:14
I figure out one of my problems with using any JavaScript Solution, and that is that anytime you have to do any Math that involves a Float, or you have to convert to a float for any reason, you are going to have precision issues, BigInt that bird showed, works great, but I could not figure out how to use it in Qml, Qt states to look for JavaScript Examples, when most do not work, BigInt is one, plus there is a "this" bug to deal with, so I switched to boost math multiprecision, I have one issue with it, another thread, but it does give me the correct answer, so thanks for all the help.
– user83395
Mar 29 at 1:02
add a comment |
QtCreator Qml JavaScript is choking on the arrow function expression, I will have to figure out how to convert them to a regular function call, unless you can update your answer to work in QtCreator, never used arrow function, I do see from researching them that they do not work in Qml, but no idea how to convert right now, will look into it, the answer is right, so it is just a matter of getting it work in Qml. Thanks, great work, did not know about this, was working on a C++ solution, like this better, a lot more precision. bugreports.qt.io/browse/QTBUG-47735
– user83395
Mar 27 at 4:53
@user83395 I updated the answer to convert arrow function into normal function. Hope it help.
– bird
Mar 27 at 5:27
Thanks, close, just add new in front of BigInt, some warning about using new before functions that start with capital letters, then I get a BigInt undefined error, looking at developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/…, it seems this is built in, google did not help find a solution, Qml JavaScript is just not the same as Web, do you know if I need to import it, if so how? Thanks for all the help, I assume you got this to work using Qt Creator, assume, you know what that means.
– user83395
Mar 27 at 5:52
My efforts in C++ gave me 1011954093357316096, which is worse than JavaScript, seems 64 bits is not enough, and that was using a Double, I will have to look into Arbitrary Precision Math Libraries next, I hope I can use BigInt, google is no help, all I can find is for Web use, not Qml.
– user83395
Mar 27 at 6:14
I figure out one of my problems with using any JavaScript Solution, and that is that anytime you have to do any Math that involves a Float, or you have to convert to a float for any reason, you are going to have precision issues, BigInt that bird showed, works great, but I could not figure out how to use it in Qml, Qt states to look for JavaScript Examples, when most do not work, BigInt is one, plus there is a "this" bug to deal with, so I switched to boost math multiprecision, I have one issue with it, another thread, but it does give me the correct answer, so thanks for all the help.
– user83395
Mar 29 at 1:02
QtCreator Qml JavaScript is choking on the arrow function expression, I will have to figure out how to convert them to a regular function call, unless you can update your answer to work in QtCreator, never used arrow function, I do see from researching them that they do not work in Qml, but no idea how to convert right now, will look into it, the answer is right, so it is just a matter of getting it work in Qml. Thanks, great work, did not know about this, was working on a C++ solution, like this better, a lot more precision. bugreports.qt.io/browse/QTBUG-47735
– user83395
Mar 27 at 4:53
QtCreator Qml JavaScript is choking on the arrow function expression, I will have to figure out how to convert them to a regular function call, unless you can update your answer to work in QtCreator, never used arrow function, I do see from researching them that they do not work in Qml, but no idea how to convert right now, will look into it, the answer is right, so it is just a matter of getting it work in Qml. Thanks, great work, did not know about this, was working on a C++ solution, like this better, a lot more precision. bugreports.qt.io/browse/QTBUG-47735
– user83395
Mar 27 at 4:53
@user83395 I updated the answer to convert arrow function into normal function. Hope it help.
– bird
Mar 27 at 5:27
@user83395 I updated the answer to convert arrow function into normal function. Hope it help.
– bird
Mar 27 at 5:27
Thanks, close, just add new in front of BigInt, some warning about using new before functions that start with capital letters, then I get a BigInt undefined error, looking at developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/…, it seems this is built in, google did not help find a solution, Qml JavaScript is just not the same as Web, do you know if I need to import it, if so how? Thanks for all the help, I assume you got this to work using Qt Creator, assume, you know what that means.
– user83395
Mar 27 at 5:52
Thanks, close, just add new in front of BigInt, some warning about using new before functions that start with capital letters, then I get a BigInt undefined error, looking at developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/…, it seems this is built in, google did not help find a solution, Qml JavaScript is just not the same as Web, do you know if I need to import it, if so how? Thanks for all the help, I assume you got this to work using Qt Creator, assume, you know what that means.
– user83395
Mar 27 at 5:52
My efforts in C++ gave me 1011954093357316096, which is worse than JavaScript, seems 64 bits is not enough, and that was using a Double, I will have to look into Arbitrary Precision Math Libraries next, I hope I can use BigInt, google is no help, all I can find is for Web use, not Qml.
– user83395
Mar 27 at 6:14
My efforts in C++ gave me 1011954093357316096, which is worse than JavaScript, seems 64 bits is not enough, and that was using a Double, I will have to look into Arbitrary Precision Math Libraries next, I hope I can use BigInt, google is no help, all I can find is for Web use, not Qml.
– user83395
Mar 27 at 6:14
I figure out one of my problems with using any JavaScript Solution, and that is that anytime you have to do any Math that involves a Float, or you have to convert to a float for any reason, you are going to have precision issues, BigInt that bird showed, works great, but I could not figure out how to use it in Qml, Qt states to look for JavaScript Examples, when most do not work, BigInt is one, plus there is a "this" bug to deal with, so I switched to boost math multiprecision, I have one issue with it, another thread, but it does give me the correct answer, so thanks for all the help.
– user83395
Mar 29 at 1:02
I figure out one of my problems with using any JavaScript Solution, and that is that anytime you have to do any Math that involves a Float, or you have to convert to a float for any reason, you are going to have precision issues, BigInt that bird showed, works great, but I could not figure out how to use it in Qml, Qt states to look for JavaScript Examples, when most do not work, BigInt is one, plus there is a "this" bug to deal with, so I switched to boost math multiprecision, I have one issue with it, another thread, but it does give me the correct answer, so thanks for all the help.
– user83395
Mar 29 at 1:02
add a comment |
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JavaScript precision just isn't good enough for your extremely large numbers. I assumed you looked into the various big* libraries that would solve the precision issue? (github.com/MikeMcl).
– Cᴏʀʏ
Mar 27 at 0:57
I was referring to this one above, it was not written for Qml JavaScript, it would take a lot of work to get it to just have no error or warnings, I started by removing "use strict", and changing the == to === and so on, but run into problems with variables not being defined before use, and fixing some of them, lead to more problems, it can be converted, never done that before, was hoping for a library that made for Qml.
– user83395
Mar 27 at 1:32
@user83395 In SO you should not add SOLVED to the title of the question, instead you should mark the question that helped you solve your problem, if instead you found the solution then we invite you to publish a solution and mark it as correct in 2 days , for more information check the tour :-)
– eyllanesc
Mar 29 at 3:32