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# Bob Nbob

##### Last seen: 1 day ago
364 total contributions since 2016

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Hello! Can you help me with this?
It seems to me like you're totally overcomplicating this. Let me know if I'm interpretting the steps of your code correctly. Th...

11 days ago | 0

Access previous iteration in while loop to derive stopping criterion for differential equation correction-prediction method
In MATLAB, you cannot access the previous iteration of a loop directly. If you want to utilize that information you need to eith...

12 days ago | 0

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How can remove Excel column by MATLAB
The simplest way is to load the excel file with xlsread, then write the data back with only the desired columns using xlswrite. ...

2 months ago | 0

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Plotting a matrix in a for loop.
With MATLAB you don't really want to perform the plot inside the loop in this case. Just save your results in a matrix and plot ...

2 months ago | 0

How to save more than the last matrix in a for cycle
You need to index Sigma_elem. Sigma_elem(:,:,i,N)=EPSM(N,1:6).*e_mat/0.6; % Or something similar

2 months ago | 0

Plotting a 3-D Matrix, but only for some points
I would suggest using scatter3 to make the actual plot. I would suggest using something like find to identify the locations of t...

2 months ago | 0

how to calculate how many rows are having numeric values in a particular cell of an excel sheet data.
Read the file with xlsread, filter the NaN values, then determine the number of the remaining values. numnumerics = sum(~isnan(...

2 months ago | 0

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Extract and code gender string as number using if loop
Just to clarify, you have 'gender' as two separate variables, once as a variable called 'gender' which will have a numeric assig...

2 months ago | 0

overly convoluted elseif condition
You can replace all of them with a single statement and indexing. if x>=1 & x<=4 y = p(x); else y = 1; end

2 months ago | 0

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How to increment matrix row only inside a nested for loop?
The solution is indexing. You can do math in your index if you need to. x((i-1)*5+j) = i*j;

3 months ago | 0

filtering data with a for loop and plot only filtered data
This can be done much more simply with logic indexing. quer = meas.ay.data; quer = quer(quer > 1.5 | quer < -1.5); plot(quer)...

3 months ago | 1

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Replace values in collumns
You can just index your matrix to reorder it, assuming all of the columns are the same type of data (i.e. all of column 6 is z2,...

3 months ago | 0

2 variable for-loop
The issue is with your definition of test. Nested for loops are totally fine. test(:,ss)=TKE_dave(:,ss); On your last loop te...

3 months ago | 1

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Error Unable to perform assignment because dot indexing is not supported for variables of this type.
You are receiving the error because you have already defined the class of the first level as a character. In order to add a seco...

3 months ago | 0

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Changing Variable in matrix
Why are you originally defining A as A = [a b c]? This isn't very common or efficient matlab usage. I would suggest starting wit...

3 months ago | 0

Could someone please optimize this code?
I don't know about 'optimized,' but I'm pretty sure you can remove the entire for loop by vectorizing. Also, suppressing your va...

3 months ago | 0

How can I assign a variable to all the columns and all the rows of a matrix?
You don't need to actually create a new variable for this, you can just use the results from size. A = randi(100,20,10); [r,c]...

3 months ago | 0

A for loop with matrix as step
I'm confused what you're trying to do. From the psuedo code you wrote it looks like you're trying to loop through each of the a...

3 months ago | 0

Choose a cell array that satisfy better some criteria
Ok, here is what I have come up with. It will probably still need some tweaking, but you should be most interested in the calcul...

3 months ago | 0

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Is the find function a robust method to determine the number of specific values in a Matrix?
That method will certainly work, and I would generally use the same concept. I would just use the sum command though to avoid th...

4 months ago | 1

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can any one explain this line of the code.
Per matrix math rules, when you add a single value to a matrix, that operation is applied to all values of the matrix individual...

4 months ago | 0

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Find all the words contained in a file and make an index
You are on the right track, but you aren't calling the word index correctly. Also, I would suggest using strfind instead of the ...

4 months ago | 0

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Describing a sum with a while loop
I'm pretty sure that adding a big number to 0 will bump you over pi on the first iteration, but maybe that's just me. I would do...

4 months ago | 0

Select value from the list by defining criteria
I would use readtable to import the data, the logic indexing to narrow down the results. data = readtable('mydata.xlsx'); redu...

4 months ago | 0

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How to make matlab variables named as excel header
It sounds like readtable might be what you're looking for. I don't think it's exactly what you're asking, but it should recogniz...

4 months ago | 0

Matrix from an array
Not sure how to do it without a loop or just defining the indices, but here's something simple. A = 1:15; for i = 1:length(A)/...

4 months ago | 0

I want to circular shift rows of ' ww ' this circular shift depend on the numbers of 'r' array in the order , when the r numbers is change the circular shift is change for the ww array rows .
If I am understanding r correctly, you want to move the respective rows from their current positions to that position plus r(i)....

4 months ago | 1

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Extract Variable/column with variable name from table
I believe you can get this as a return. T.Properties.VariableNames % T is the table variable Additionally, because you're putt...

4 months ago | 0

My code is generating this error " Index exceeds matrix dimensions" . Apparently it looks fine. Still can not figure out the problem.
dfdc1(i,j) = (L/M) - M*(log(1 - c1(i,j) - c2(i,j)) - log(c1(i,j)))/M; c1 and c2 are defined as single values (0.1 and 0.0001), ...

4 months ago | 0

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Question

Extracting data from ascii file using regexp
I have an ascii file which produces the following text. 1 \$FLAG1 NP1=8.,NP2=1.,P2=2.36,P3=3000000., 2 P1=0.,4....

4 months ago | 0 answers | 0