James Tursa

Last seen: Today | 自 2007 起处于活动状态

Followers: 0 Following: 0

消息

Interested in external applications, mex & engine applications with Fortran, C, C++, etc, particularly in the areas of speed improvement and memory management efficiencies.

统计学

All

查看徽章

Feeds

已回答
Order terms in symbolic poly converted to string
Brute force if you need the string for some reason? syms x ex = taylor(exp(x),order=3) [C,T] = coeffs(ex) terms = fliplr(C.*...

5 days 前 | 2

已回答
How can we convert a datetime into a string that represents a Unix timestamp in nanoseconds?
Another workaround that avoids the lossy duration type issues and doesn't need the messy struct solution for this particular cas...

1 month 前 | 0

已回答
Write a function called freezing that takes a vector of numbers that correspond to daily low temperatures in Fahrenheit. Return numfreeze, the number of days with sub freezing
Hint: Is it freezing when the temperature is above 32 or below 32? And what have you coded?

2 months 前 | 2

已回答
How to do differentiation in Matlab
Are you just asking for piecewise linear differencing for derivative calculations between the points? E.g., THT = 0:12:360; L...

2 months 前 | 0

| 已接受

已回答
Matlab got this wrong: Limit as n goes to infinity: (1+(i/n))^(n^2). Matlab says it's exp(2), which is wrong. Pls confirm.
I have been looking at this for a couple of days now and have finally convinced myself that this limit doesn't exist and MATLAB ...

2 months 前 | 0

已回答
How can I find index of element in array?
To find the index of a specific integer value (without roundoff error) in an array of integers, use the "find" function and == o...

2 months 前 | 33

| 已接受

提问

Duration type doesn't preserve seconds accuracy
I've been working on some time conversion routines and ran into an issue I didn't expect. Basically, the duration type doesn't p...

2 months 前 | 2 个回答 | 0

2

个回答

已回答
Rank value matrix from 3d Matrix
Might be easier to permute first so that your 2D matrices are in the first two spots. Then simply use sort() to get the rank ind...

3 months 前 | 0

已回答
Error with matrix calculation
We don't have all the variables necessary to run your code, but guessing that maybe you need element-wise divide instead of matr...

3 months 前 | 1

已回答
Unable to resolve the name 'half.typecast'
half is an opaque data type in MATLAB, not a regular numeric type like double and single. I tried to get TMW to change this to a...

3 months 前 | 1

| 已接受

已回答
What does it mean "/Multiple" after variable name in *.mat file?
If the file is written by a 3rd party tool, it is probably written in uncompressed format. In that case, and if the /Multiple is...

3 months 前 | 1

| 已接受

已回答
Having issues writing matrix to a binary file.
@Rikin You forgot to read in the sizes. You only read in the double data. The two int32 variables at the front obviously were pa...

3 months 前 | 1

已回答
How to write a matrix with elements 10,30,10
Use brackets M2 = [10,30,10]

3 months 前 | 0

已回答
an ode with arguements
Create a new function handle with your extra stuff. E.g., mufunT = @(eta,f) mufun(eta,f,guessT) [eta, f] = ode45(mufunT, [lins...

3 months 前 | 0

已回答
Column to matix In matlab
Depends on how your data is currently stored. Suppose the data is currently in a vector v. Then matrix = reshape(v,50,10).'

3 months 前 | 0

已回答
How do I process a string class in a mex function?
Strings are opaque objects (like classdef) and there are no API functions to get pointer access to the data areas. I am unaware...

3 months 前 | 0

已回答
How to convert dates into Julian dates?
Based on your comment that you are expecting numbers in the range of 273,287,298, etc., if what you are after is actually "day ...

4 months 前 | 0

已回答
How to create for loop for calculating euclidean distance of a matrix?
Does pdist() do what you want: https://www.mathworks.com/help/stats/pdist.html?s_tid=doc_ta

4 months 前 | 0

已回答
converting 3d matrix into a cell array
x = rand(1001,259,259); result = arrayfun(@(k)squeeze(x(k,:,:)),1:size(x,1),'uni',false); size(result) size(result{1}) But, ...

4 months 前 | 0

已回答
How to implement the Central Difference method integrator for a two body problem?
You have: altitude tangential velocity If you just want the orbital period, you can calculate as follows using the Vis-Viva e...

4 months 前 | 0

已回答
Can multiple versions of MATLAB be installed on the same Windows PC using the same license number for code compatibility?"
Multiple MATLAB versions can be installed on the same machine as long as your license permits it. Both can even be run simultan...

4 months 前 | 0

已回答
How to calculate the angle between two 3D vectors?
See a discussion here (includes a tiny angle example): https://www.mathworks.com/matlabcentral/answers/101590-how-can-i-determi...

4 months 前 | 1

已回答
Double precision: Why does fprintf print "extra" wrong non zero digits?
The "extra" digits that look incorrect to you are simply the result of doing an exact conversion of the actual floating point bi...

4 months 前 | 1

| 已接受

已回答
What does MATLAB actually do when switching precisions?
When converting from IEEE single to double, the sign bit is retained, the exponent bits are adjusted to match the same exponent ...

4 months 前 | 2

已回答
I want to solve ODE for a complex systems in a rk4 method
Just turn all the y( ) stuff into row or column vectors. E.g., suppose we use column vectors, then something like this ... y = ...

5 months 前 | 0

| 已接受

已回答
quat2angle / atan2 strange quadrant change when calculating angle
You don't show us your code, but in general I would note that angle changes like this are sometimes the result of whole quaterni...

5 months 前 | 0

已回答
Active rotation with quaternions: from initial orientation given with Euler angles get the new orientation after an active rotation described by the qr quaternion.
Yes, for your convention q' = q * qr is mathematically correct. But note that this formula only works for certain quaternion co...

5 months 前 | 1

| 已接受

提问

Conjugate of Symbolic Root doesn't change anything
Reference question first asked here: https://stackoverflow.com/questions/78010011/matlab-bug-with-root-and-conj Basically, the...

5 months 前 | 1 个回答 | 1

1

个回答

已回答
sparse matrix entries are not displayed correctly
I finally finished my sparse matrix integrity checker. You can find it in the FEX under the name SAREK (I think you will be able...

6 months 前 | 0

已回答
the tranpose of transpose doed not equals the original matrix
I finally finished my sparse matrix integrity checker. You can find it in the FEX under the name SAREK (I think you will be able...

6 months 前 | 2

加载更多