Finding the mean along X axis on plot?

Hello. I am trying to find the mean along the X axis as follows.

As shown in the plot, I would like to find the mean of the 'GS-TAS' scatter plots on different altitudes. For example, by drawing a line perpendicular to the Altitude axis on 2.35x10^4 feet, you can see corresponding GS-TAS values. I would like to find the mean of those values, on all altitude levels then plot it against the altitude. Is it possible? Any simple methods to do it? Thanks.

Answer 1

[Walter Roberson]

level_spacing = 500;
Alt = .... %vector of the altitudes of each data point
GSTAS = ... %vector of the GS-TAS for each data point

altbins = 1 + floor(Alt(:) ./ level_spacing);   %convert altitude to relative level number

mean_gstas = accumarray(altbins, GSTAS(:), [], @mean, NaN);  %all the real work

altlevels = level_spacing * (0:length(mean_gstas)-1);

plot(altlevels, mean_gstas, '*-');

With this code, any altitude level for which there is no data will not show a connecting line; no interpolation is implied. If you want connecting lines then change the plot() to

hasdata = ~isnan(mean_gstas);
plot(altlevels(hasdata), mean_gstas(hasdata), '*-');

[bio lim]

Hello, thank you very much for your answer. The problem is, I am working on a 1x57 structure array (the file is attached). I am working on the two fields, 'Altitude' and 'wind (GS - TAS)', basically plotted for every index. Should I change my structure to cell array and continue with your code or is there better way?

Thanks again. Sorry, I am a matlab beginner.

[Hugo]

Hi coffee You can get the vectors that the answer of Walter require as follows. For example, in the case of the altitude, do this:

Alt = cell2mat(arrayfun(@(x)data2(x).altitude',1:numel(data2),'UniformOutput',false));

This certainly looks overly complicated for a reason: The data in your fields are column vectors. Should they be row vectors, you could have obtained the same by doing this:

Alt = [data2.altitude];

Hope this helps. Hugo

[Walter Roberson]

Alt = vertcat(data2.altitude);

should do fine with column vectors.