MATLAB: Wind_rose execution

I try to run the porgram but it show following error, I am using Matlab 2010a, how to correct it? Attempted to access i(1); index out of bounds because numel(i)=0. Error in ==> wind_rose at 238 d=dcircles(i(1));

Best Answer

It looks like you're using a File Exchange submission called wind_rose. There's really no way to debug the problem without seeing how you're calling this function.

It looks like the line prior to the one giving the error is returning an empty array; one reason I could think of for that is that d (defined on the line before that) is NaN, but I can't see how that would occur.

Try setting a breakpoint on the line that gives the error and running the code. When it stops on that line and enters debug mode, look at the values of d and b.

Related Solutions

MATLAB: Plotting windrose using Matlab

Shital - there are two options for specifying wind direction using wind_rose from the File Exchange: standard (which is the default) and meteo. Using examples such as

 v = 30*rand(10000,1);
 d =   rand(10000,1);
 wind_rose(d,v)

shows the wind at the east, when I expect it to be at the north. Changing the wind directions to

 d = 60 + rand(10000,1);
 wind_rose(d,v)

shows the wind at roughly 30 degrees from north. This suggests that the author of the code is using a counter-clockwise from east system, where 0 degrees is at east (along the x-axis), ninety degrees is at north, etc.

You are probably expecting a clockwise from north system where 0 degrees is at north, 90 degrees is at east, etc. To get around this you can just subtract your direction vector from ninety degrees like

 d = 90 - d;

If you re-use the examples from above, then winds appear correctly relative to north (y-axis).

If you decide to change the direction type from the default of standard to meteo, then this appears more of a meteorological wind direction convention. If the wind direction vector is primarily northern wind directions, then the wind is blowing to the north and so coming from the south. So you using

 v = 30*rand(10000,1);
 d =   rand(10000,1);
 wind_rose(d,v,'dtype','meteo')

will show winds in the south of the figure, since they are blowing to the north and so coming from the south. Likewise

 d = 60 + rand(10000,1);
 wind_rose(d,v,'dtype','meteo')

would show the winds coming from the south-west as they are blowing to 60 degrees from north

Best Answer

Related Solutions

MATLAB: Plotting windrose using Matlab

Related Question