How can I plot a matrix using pcolor and colorscale as log?

I have a timeseries matrix data of a lidar. I want to plot the time series keeping colorbar as logscale.

I have written the following code but it shows an error

load time_June.mat

load elevation_June_5km.mat

load backscatter_June_5km.mat

load raw_backscatter_June_5km.mat

figure(1);

pcolor(time_June, elevation_June_5km, backscatter_June_5km); shading interp

c = colorbar;

caxis([10^-7 10^-4]);

set(gca, 'ColorScale', 'log');

c.Label.String = 'Attenuated backscatter coefficient (m^{-1} sr^{-1})';

c.Ruler.Scale = 'log';

c.Ruler.MinorTick = 'on';

colormap jet;

set(gca, 'YDir', 'normal');

xlabel('Time (LT)');

ylabel('Altitude (km)');

axis tight;

set(gca, 'FontName', 'Times', 'FontSize', 14);

startDate = datetime(2023, 6, 16);

endDate = datetime(2023, 6, 25);

xlim([startDate, endDate]);

Error:

Warning: Error creating or updating Surface

Error in value of property CData

DataSpace or ColorSpace transform method failed.

[Sahas]

Hi @AMIT SINGH CHANDEL,

I've taken a look at the code and ran a few simlations with dummy data. But to generate the given errors, it would requires the specific files to load the workspace variables. Could you please share those files so that I could further investigate for the cause of this behaviour?

[AMIT SINGH CHANDEL]

Hi Sahas

I have attached the files for you to look over.

Answer 1

[Sandeep Mishra]

Hello AMIT SINGH CHANDEL,

I understand you are encountering an error while plotting the time series data with the 'ColorScale' property set to logscale.

Kindly follow the below workarounds to resolve the issue:

• I observed that the ‘backscatter_June_5km.mat’ file contains some NaN values, which are causing the issue. To resolve the error, you can replace the NaN values in your 'backscatter_June_5km.mat' file with any double integer value. Refer to the below example code snippet which replaces NaN  values with a fixed value 2.

% Replacing NaN values to a fixed value.
backscatter_June_5km = fillmissing(backscatter_June_5km, 'constant', 2);

• It appears that MATLAB is handling the NaN values effectively after R2022a. Therefore, updating your MATLAB to R2022a or a later version might also resolve the issue.

I hope this will help you resolve the error and successfully plot the time series.