Faulty result on contour map

I have just created a contour map, but some values are false. I don't know where is my error? May you help me? My dataset at the attachment.
data=xlsread('data.xlsx')
rpm=xlsread('data.xlsx','A3:A10')
kw=xlsread('data.xlsx','B2:I2')
bsfc=xlsread('data.xlsx','B3:I10')
a = surf(rpm, kw, bsfc);
[a,b] = contourf(rpm, kw, bsfc);
clabel(a,b);
xlabel('rpm');
ylabel('kW');

2 Commenti

Could you be more specific about the areas that are "false"? The only difficulty I see is the way the 250 has a branch that ends abruptly.
Which MATLAB release are you using?
Have you tried setting the figure renderer to different things, zbuffer and painters and opengl ?
For example, at 2000 rpm and 60 kw, BSFC value must be 0, but the same point on the contur graph shows this point as 350 g/kWh.
I am using MATLAB 2008 and i didn't try anything about this process.

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Risposte (1)

Not 100% sure what you mean by "some values are false", but I suspect that you've just transposed x and y axis. Does
a = surf(kw,rpm, bsfc);
[a,b] = contourf(kw, rpm, bsfc)
do what you want?
If not, then please elaborate on what you don't like about the graph and what you think it should look like.

4 Commenti

Yes, this works. But i should replace x with y axis.
Volkan Yangin
Volkan Yangin il 30 Nov 2016
Modificato: Volkan Yangin il 30 Nov 2016
Problem has been solved with using transpose of a matrix. Now i am taking correct BSFC values on contour map.
Guillaume
Guillaume il 30 Nov 2016
You should accept Daniel's answer to give him credit and to tell others that it is now solved.
A fuel consumption of 0 at high load? I want your engine! Or perhaps the BSFC should be NaN instead of 0 to indicate that the particular test point was not tested / could not be reached.
Thank you Guillaume At the lessons, we write 0 at over of the full load curves. So, i wrote as 0, too.

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Richiesto:

il 29 Nov 2016

Commentato:

il 3 Dic 2016

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