MATLAB MATLAB Filter command for BSFC map

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The discussion revolves around creating a Brake Specific Fuel Consumption (BSFC) contour plot in MATLAB using engine data from a dynamometer. The user shares their MATLAB code for generating the plot, which includes creating a mesh grid and using griddata for interpolation. They seek advice on using the filter function to smooth the curves in their plot. Another participant suggests an alternative approach using MATLAB's built-in curve fitting tool, highlighting its user-friendly interface and effectiveness in producing smooth interpolated results with fewer data points. The conversation emphasizes the importance of data smoothing techniques in enhancing the visual quality of engine performance plots.
Alex91
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Hi all,

I have made a BSFC plot in MATLAB with engine data tested on an eddie current dyno, The code I used for it is:

>> NP=40;
>> [RP TP]=meshgrid(linspace(min(RPM),max(RPM),NP),linspace(min(Torque),max(Torque),NP));
>> BSFC_IT=griddata(RPM,Torque,BSFC,RP,TP);
>> NC=12;
>> Fig1=figure;
>> [CT HT]=contourf(RP,TP,BSFC_IT,round(logspace(log10(210),log10(400),NC)));
>> colorbar;
>> %clabel(CT,HT);
>> xlabel('Engine Speed (rpm)')
>> ylabel('Torque (Nm)')
>> title('Contours of BSFC (g/kWh)')

With all my data this gave me a contour plot that looks like the image I have attached and this is after fiddling with all of the data to make it look 'pretty'.

I know you can use the filter function to smooth out plots, so my question is, how can I use the filter function to smooth out the curves with the complex code I have?

Any help is much appreciated.

Thanks

Alex
 

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Hello, I was working on the same issue. I tried some tools like gridfit and griddata, but the best result was using the curve fitting tool built in Matlab. If you have a modern version it is has a visual interface, you can find it under apps toolstrip. it is so simple you just specify x,y,z data and give good interpolated smooth results, I was able to plot this with only 60 data readings. Hope this helps!
bsfc.png
 

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