Respected @tomleslie,

It is possible to fill the region with the color scheme in odeplot.

In this ode plot, how to fill the region with color scheme "HSV".

display( [seq(plt[i], i=1..11)],size=[600,500],filled=true,axes=boxed,colorscheme=[green,red]);

Dear @acer 

Thank you for showing different plots for the same equation.

Have a good day

Dear @Carl Love 

The plots are coming very nice.

Thanks for your precious work and continuous support.

Have a good day.

Dear @Carl Love 

Are you got any idea about Nu* values shows as colors?

I share a few things here, if it is irritating I apologize to you.

in Matlab "colormap" comment is there.

it will take the default, higher value as a red color and lower value as a blue color in the contour plot.

in -D(theta)(1) = `Nu*` some parameters generate values, based on his influence in temperature (theta) equation.

for eg. in this figure,

Ha as a sequence of 2..8.

Rd minimum then rate heat transfer is high(red color line).

increase the Rd value decrease the rate of heat transfer(green and blue color line).

the similar thing reflected in the 3d plot also

Rd 0-2 and Ha 8-12 the rate of heat transfer was high, after the Rd 2 it decreases the rate of heat transfer so yellow color is there.

in contour 5 ( 'grid'= [25,25], 'contours'= 5, 'filled', )regions are there, each region we need to give a different color.

I hope it will helpful to you.

Have a good day

Dear @Carl Love 

Let me explain through the picture above,

Nu starts at 4.5, let takes as 100 heat (assume), so there is the red color.

Nu = 3.75 has heat 80, so there is yellow color.

When the Nu = 2,  the heat reaches 0 is, there is the blue color.

Nu 4.75-2 heat 100-0, so color red-blue.

so they use coloring to show the variation.

in the above coding contour plot  'coloring'= ['yellow', 'orange'], 

line color  'color'= 'green', 

in the surface plot, there is no any specific color.

we need to use the same color on the surface and contour.

I hope you know what I'm asking now.

Thankyou

Dear @Carl Love 

Low heat exchange should be blue and high heat red. There should be some colors to indicate the heat transfer between this.

in my previous comment, I enclosed a graph.

in that the show clearly high heat (red)  to the low heat (sky), and the transformation (orange, orange green). 

Thanks for the continuous support.

Dear @Carl Love ,

Previously, I understood wrong. now the output coming properly. (`*`@ op)

Thank you.

Dear @Carl Love 

 Dear   @Carl Love ,

Here the meaning of the color was high heat transfer to low heat transfer. and both the 2D and 3D graphs are represented the influence of 2 parameters affect the heat transfer.

so need to show both the 2D and 3D are the same color, which represents the heat transfer.

for example,

Thanking you have a good day.

Dear author,

how to give the surface and contour both have the same color.

  'coloring'= ['yellow', 'orange'], 'color'= 'green', 

in coloring, insted of ['yellow', 'orange'] i replaced proc(RX,RY) RX*RY end proc but its not working.

Dear @Carl Love 

The answer is coming but it shows "model is not of full rank".

Thanking you

Dear author,

statistical fit shows an error.
I tried so many ways, but error correction failed.

Thanking you, Have a good day.

Note: using maple version 18(maple 18)

statical_fit.mw

Dear @Carl Love,

Thanks for the quick reply.

I got it.

Thanks a lot.

Dear author,

Here the 3D plot was the combination of surface and contour. how to plot only the contour 2D graph Ha against S. 

Thanking you.