Plotting column of a matrix from a string.

I have a variable which contains data loaded from a matfile...

loadedContent=load('C:\Users\ringo\AppData\Local\Temp\temp3388979983628797436tmp\mv_20.mat');

in that matfile is a 360000x5 double called dat. I need to plot a column from dat using a char variable. I can plot all of the columns by creating a char variable

plotsall = 'dat';  
plot(loadedContent.(num2str(plotsall)));

but if i try

plotcolumn = 'dat(:,1)';  
plot(loadedContent.(num2str(plotcolumn)));

i get an error

Reference to non-existent field 'dat(:,1)'.

The only way round it I can think is to actually load the data into the workspace and plot using

plot(eval(plotcolumn));

this works, but using the eval function is never good... i just can't think of a way round it. Any ideas?

If you want/need anymore info as to why i'm doing this, a short version is making gui-->user locates file--->contents of file loaded into a list box--->user selects which data to plot--->if the data has more than one column a popup asks them which column to plot--->data gets plotted.

If you need anymore info, please let me know. Cheers

Answer 1

[Adam]

    plot( loadedContent.( plotsall )(:,1) )

seems to work. I wasn't aware it could be done because usually Matlab doesn't support chained indexing, but since loadedContent.( plotsall ) evaluates to a variable you can index it as any other variable.

[Rich]

Excellent. Thank you very much