Walter Roberson

Last seen: Today | Active since 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

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Answered
how can I plot this figures
https://www.mathworks.com/help/matlab/ref/histcounts2.html can be used to calculate the counts for density plot purposes. images...

5 hours ago | 0

Answered
How to concatenate/combine a list of images in one mat.file (convert picture 1 into picture 2)
What you are asking for is possible but not recommended. You are asking to open the variable browser on each field of the struct...

6 hours ago | 0

Answered
Fmincon Error Message please help!
In order to get that error at that line of code, your function Obj_Complex had to have generated an error message when evaluated...

8 hours ago | 0

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OPEN(OPEN_COUNT,:)=insert_open(xNode,yNode,path_cost,goal_distance); how to solve this error please help fast
https://www.mathworks.com/matlabcentral/fileexchange/26248-a-a-star-search-for-path-planning-tutorial has the source code

16 hours ago | 0

Answered
How can i reshape a matrix
reshape(permute(M1, [1 3 2]),[],size(M1,2))

21 hours ago | 0

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Answered
How to show the cross cursor (instead of arrow) when clicking on the UIAxes in the App designer? How to save several coordinates when clicking for times via upButtonfunc?
https://www.mathworks.com/matlabcentral/answers/496366-how-do-i-change-the-pointer-property-on-a-ui-figure for information on...

21 hours ago | 0

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Answered
How to obtain coordinate using 'ginput' in the UIaxis when coding in Appdesigner
See https://www.mathworks.com/matlabcentral/answers/392617-how-can-i-use-ginput-in-app-designer#answer_504862 for code. Requires...

21 hours ago | 1

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Answered
Unable to run code due to an error in 'Fadeeva_m' function
you need to run the build script to compile faddeeva_w https://www.mathworks.com/matlabcentral/fileexchange/38787-faddeeva-pa...

1 day ago | 0

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How to convert negative numbers in parentheses (bank-formatted text) to numbers with minus sign?
Use detectImportOptions and then modify the options to set that column to character or string type. Then regexprep() the column,...

1 day ago | 0

Answered
WHEN I AM EXECUTING THIS CODE I GET A JULIA IMAGE .HOW CAN I READ THIS IMAGE IN THE CODE AND USE THIS TO GENERATE KEY FOR ENCRYPTION CRYPTION
Bre = im2uint8(rescale(B)); imgfile = 'B.png'; cmap = jet; Bc = ind2rgb(Bre, cmap) ; imwrite(Bc, imgfile) I =...

1 day ago | 0

Answered
Extracting variable data at specified location from .nc file
loc = [i j 1 1]; count = [1 1 inf inf]; varname = 'temp'; tempdata = ncread( ncfile, varname, loc, count); However...

1 day ago | 0

Answered
Invalid expression. When calling a function or indexing a variable, use parentheses. Otherwise, check for mismatched delimiters.
Go through your expression character by character, counting brackets. Each time you have a ( character increase the count by 1. ...

1 day ago | 0

Answered
how to get decimal answers?
sympref('FloatingPointOutput',true); I personally do not recommend this approach, as I find that there are many cases where...

1 day ago | 0

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How to display an expression using an array
char(der) rather than num2str(der) The result of diff() applied to a symbolic expression is a symbolic expression, not a numb...

1 day ago | 0

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using inputdlg function in user defined function
"I would like to apear the box only one and keep on the simulation run" That is not possible with inputdlg() See <https://...

1 day ago | 0

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Hello.. I am working on detecting lung nodules and I would like to know how to convert the lung nodule extracted from a CT image into a 3D image.
Take the binary image and use bwtraceboundary or bwboundaries to get the coordinates of the edge pixels. Take each outer edge's...

2 days ago | 0

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Download a file from a website?
See websave webread urlwrite ftp and mget sftp

2 days ago | 0

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i used format shortg but still the result is come in e format and fraction
a2 come in the fraction form That is expected for format short. When using format short, all values greater than 100000 that ar...

2 days ago | 0

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Answered
fsolve for equations system with syms
fsolve must be applied to a function handle (or a character vector that names a function.) There is no fsolve for symbolic expre...

2 days ago | 0

Answered
Extracting data from part of a plot
Do they need to be extracted from the plot or can we use x and y instead? Is the number of groups known? This code assumes that...

2 days ago | 0

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How can I easily and automatically arrange text objects on a figure so they are not placed on top of each other or plots?
The significantly easier solution to this problem is to use annotation 'arrow' and 'text' to put labels outside of the plot that...

2 days ago | 0

Answered
How to access properties of objects instantiated between different classes in multi-window matlab app designer
app2 and app aux each have constructor methods. Change the constructors to accept an option parameter which is the handle of the...

2 days ago | 0

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Getting Different plot values
Your data is not at all in pairs. Your data is in groups of 10 -- the data starts at 0 and returns to 0 each 10 entries. You ta...

2 days ago | 0

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Answered
Dot indexing is not supported for variables of this type??? Parfor loop, and global variable
You can use parallel.pool.Constant to send a copy of the data to all workers, and you can use parfevalOnAll to run a function on...

2 days ago | 0

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Your software can solve transport matrices of more than 9000 cells of variables?
Generally speaking: There are some algorithms that require storage space that is linear in the number of variables being optimi...

3 days ago | 0

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Error using Distributed Parameter Line Block
See https://www.mathworks.com/help/physmod/sps/powersys/ref/powergui.html The default Sample Time is 50e-6 seconds; you need t...

3 days ago | 0

Answered
Object returning its field possible?
See https://www.mathworks.com/help/matlab/matlab_oop/extend-built-in-class-operators.html

3 days ago | 0

Answered
How to generate m code for a variable
If the variable is double precision and is at most 2 dimensions, then you can use mat2str to construct the right hand side aa =...

3 days ago | 0

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how do I swap both axes in the current plot
You have three options: * you can solve U for y, taking caution because it will be multi-valued * you can use hg transform g...

3 days ago | 0

Answered
Meta question about using this forum
The questions here that get the most response are the ones that post code and error message, and data files help too. Questio...

3 days ago | 1

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