How can I plot scatter graphs in a for loop?

I have a large data set. I am trying to use a for lop, to be able to select which coloumn i want to keep and which ones i want to discard, all depending on the user input.

I managed to do that part, i believe.

Now I am trying to get an average value for each coloumn and plot the results in a scatter graph. I tried to do this using a for loop.

But there is only one data set that appears on my scatter graph, so I assume it cancels the ones that were before that last point. I used hol all, hold on and draw now, but could not get it to work. Also I would like add a line of best fit for the scatter graph for each data set and save slope and intercept numbers in a table.

I managed to do do the line of best fit and slope, intercept before, but not since I am trying to use for loops, so I put my old code segments in a comented out section.

In the first version of the code, i just determined the coloumns ( channels ) i want to use in the code, not depending on user input.

I cannot upload the excel file that I use, because it is too big. i tried to compress, but did not work

Answer 1

[David Hill]

Assume you have your data in a matrix, M. Assume you want a scatter plot of the column vs. mean of each column.

scatter(1:size(M,2),mean(M));

[Lala0099]

but using this still does not make my graph of multiple data points in the same scatter in the for loop, but only of the last set

[David Hill]

It plots the mean of each column on the scatter plot and does not need to be in any for-loop. If you want more points plotted on the scatter plot, then I really don't understand what you want.

[Helder Maranhão]

Hi. I think understand the question. I have the same issue.

Imagine that you have a for loop

n=1
for k=1:20
    y=n+1
    n=n+1
end
scatter(k,y)

So imagine that you want to plot the y for each k from 1 to 20.

But in Matlab it will appear the last value for k.

How can we plot k from 1 to 20?

Could someone help?

Thank you

[Rik]

@Helder Maranhão your code overwrites the value of each parameter every iteration. You should learn to use arrays.