Community Profile

# Walter Roberson

Last seen: Today Con actividad desde 2011

I do not do free private consulting. If you want to bring my attention to something, send a link to the MATLAB Answers location. I am currently caught up to T0099119; if you are waiting on a reply from me for an older issue, please send me a reminder.

Programming Languages:
C, MATLAB, Shell, Perl, Fortran
Spoken Languages:
English

All

Ver insignias

#### Content Feed

Ver por

Respondida
Files added to path won't run unless I rename them first.
How are you creating the new script? If you are creating it outside of MATLAB then check Preferences -> Editor/Debugger -> Auto...

alrededor de 1 hora hace | 0

Respondida
Remove Whitespace & Text From Cell
See https://www.mathworks.com/help/matlab/ref/matlab.io.text.delimitedtextimportoptions.setvaropts.html#d124e755396 for the impo...

alrededor de 2 horas hace | 0

Respondida
Is there any problem with secant method in this code as i am not getting the required plot
Your odes are generating infinite results early on. You are getting NaN for all c values. WIth the below small modification to ...

alrededor de 3 horas hace | 0

Respondida
Help on simplifying trigonometric equations
syms c1 c2 k1 k2 l1 l2 x1 x2 eqns = [k1*sin(c1)+k2*sin(c2-c1) == l1*cos(x1) - l2*cos(x1+x2) k2*cos(c2-c1)-k1*cos(c1) =...

alrededor de 3 horas hace | 0

Respondida
Stuck in exponential notation format
format long g for Percentfailtemp = [0.011 0.11 1.1 11 110 110.234 100*(1-eps)] fprintf('Failed due to temperature %0.1d\n...

alrededor de 3 horas hace | 1

| aceptada

Respondida
How to display square root symbol instead of decimal.
sqrt(sym(5)) This requires the Symbolic Toolbox. Also, display of the square root symbol itself instead of 5^(1/2) requires th...

alrededor de 4 horas hace | 0

Respondida
how to convert mat file of impulse signal to wavefile?
fs = 1000; t = 0 : 1/fs : 10; impulse = t==2; audiowrite('impulse.wav', double(impulse), fs);

alrededor de 4 horas hace | 0

Respondida
Limits of polar plots axes
You are using polar() which is the older function that uses cartesian axes. It is difficult to customize. We would normally rec...

alrededor de 5 horas hace | 0

Respondida
Isolate horizonal part of curve
Declare your horizontal cutoff to be the place where abs() of the gradient is less than some threshold. If necessary, low-pass f...

alrededor de 5 horas hace | 0

Respondida
Difference between solve result
When you solve() and you do not specify the names of variables to solve for, the solve() uses symvar() and takes as many variabl...

alrededor de 8 horas hace | 0

Pregunta

Unexpected slowdown using () indexing
format long g NULL = 0; counter = 0; start = tic; while toc(start) < 10; NULL; counter = counter + 1; end; counter/10 NULL =...

alrededor de 9 horas hace | 0 respuestas | 2

### 0

respuestas

Respondida
Upper bound curve that passes through the extreme (highest) points
Use boundary possibly changing the alpha coefficient.

alrededor de 11 horas hace | 0

Respondida
Unable to populate trip usage tripusage=zeros(1,288) with my result tripusage(k)= (p1*x^2 + p2*x + p3) *fivemindist;
x=temp{k}; variable temp with lower case T is not defined. You have a variable Temp with upper case T

alrededor de 12 horas hace | 0

Respondida
Writetable logical table to excel as zeros and ones
Write out double() of the logical array.

alrededor de 12 horas hace | 0

Respondida
Transformation this equations to equations MATLAB
Use sin() and cos(). Powers are .^ Dot to multiply is .* Use () for grouping and priority There is no implied multiplic...

alrededor de 12 horas hace | 0

| aceptada

Respondida
How to find the number of non-NaN elements in a column that are NaN in the last column, in MatLab?
isnan(YourMatrix(:, 3)) & ~isnan(YourMatrix(:, 4))

alrededor de 12 horas hace | 0

Respondida
How can I measure the time it takes to break a cryptographic algorithm by brute force attack?
timeit() However unless you deliberately using a very small key, you would need to estimate the time instead of measuring it....

alrededor de 22 horas hace | 0

| aceptada

Respondida
How to set the same grid size of the axis for different plots?
https://www.mathworks.com/help/matlab/ref/pbaspect.html https://www.mathworks.com/help/matlab/ref/daspect.html You can set...

alrededor de 23 horas hace | 0

Respondida
How to enlarge/Scale/Increase size of a contour plot
The contour plot is made as large as possible as will fit inside the axes after taking into account axes labels and tick labels ...

alrededor de 23 horas hace | 1

Respondida
Could someone help me to import individual jpeg images embedded in a gif image into each slide in a PowerPoint file? I use exportToPPTX.
Images = imread(Gif, 'frames', 'all'); .gif files are always indexed images. In the special case that the frames were grayscal...

1 día hace | 0

Respondida
Viewing Symbolic Matrix Entries in Variable Tab?
No, No there is no way to do that. If you temp = arrayfun(@char, YourSymArray); openvar temp then you will be able to see ro...

1 día hace | 1

| aceptada

Respondida
How to simplify too much of if
Use look-up tables. For example the final elseif can be encoded as {[40 50 55 60 42 45 80 35 37] [40 41 44 60 32 36 80...

1 día hace | 0

Respondida
Is there a way to reduce Timer period to less than 1 ms?
You would need to reimplement timers.

3 días hace | 0

| aceptada

Respondida
Find doesn't seem to work with Matrix larger than 127x127
I am certain that find works. I speculate that you are putting the values together in an array with values of datatype int8. Whe...

3 días hace | 2

| aceptada

Respondida
Accessing the url address of images in Matlab Drive
The files on matlab drive cannot be remotely accessed individually. Even if you publicly share a folder, the share mechanisms do...

3 días hace | 0

| aceptada

Respondida
How can I find the Time for specific values of Voltage (with a small tolerance)?
find(abs(data-target)<=tolerance) Or ismembertol()

3 días hace | 0

| aceptada

Respondida
I would like to extract x,y,z coordinates of any 3 atoms from a pdb file. How to rectify this error and make it generalized?
% N = range of indices for example N=1:7; Q = [ubq.Model.Atom(N).X; ubq.Model.Atom(N).Y; ubq.Model.Atom(n).Z].'; This...

3 días hace | 1

Respondida
Dynamic plot in real time
pick nominal x coordinates for the endpoints of the see-saw. Create a line that has those as the x coordinates and has the "curr...

3 días hace | 0

Respondida
Error: File: project_01.m Line: 61 Column: 26
elseif Hexa_number_small = Hexa_row_small * (Hexa_number - 1); elseif must be followed by a condition, not an assignment.

3 días hace | 0

Respondida
Error in ode45 (line 115) odearguments(FcnHandlesUsed, solver_name, ode, tspan, y0, options, varargin);
delta = 1; That is a numeric scalar. Valid indices for it are numeric 1, logical true, logical false, and the empty vector....

3 días hace | 0