- #1
evgenx
- 14
- 0
Hi,
I faced a problem (in Mathematica) when trying to plot a partial
derivative of a functiona (of two variables) obatined by "Interpolation".
More precisely, here is my input:
surf=Interpolation[{
{{160.0, 160.0}, 2.852688},
{{160.0, 170.0}, 2.827547},
{{160.0, 180.0}, 2.818931},
{{160.0, 190.0}, 2.826640},
{{160.0, 200.0}, 2.851483},
{{170.0, 160.0}, 2.861634},
{{170.0, 170.0}, 2.832750},
{{170.0, 180.0}, 2.822240},
{{170.0, 190.0}, 2.830275},
{{170.0, 200.0}, 2.858395},
{{180.0, 160.0}, 2.862344},
{{180.0, 170.0}, 2.831671},
{{180.0, 180.0}, 2.820786},
{{180.0, 190.0}, 2.831775},
{{180.0, 200.0}, 2.862605},
{{190.0, 160.0}, 2.857940},
{{190.0, 170.0}, 2.830020},
{{190.0, 180.0}, 2.822137},
{{190.0, 190.0}, 2.832657},
{{190.0, 200.0}, 2.861574},
{{200.0, 160.0}, 2.850865},
{{200.0, 170.0}, 2.826201},
{{200.0, 180.0}, 2.818547},
{{200.0, 190.0}, 2.827127},
{{200.0, 200.0}, 2.852228}
}]
s1=Function[{a,b},surf[a,b]]
da=Function[{a,b},D[s1[a,b],a]]
Plot3D[da[a, b], {a, 175.0, 185.0}, {b, 175.0, 185.0}]
When running this input Mathematica gives the error:
General::ivar: 175.00071499999999` is not a valid variable
Any help will be greatly appreciated !
Many thanks!
Evgeniy
I faced a problem (in Mathematica) when trying to plot a partial
derivative of a functiona (of two variables) obatined by "Interpolation".
More precisely, here is my input:
surf=Interpolation[{
{{160.0, 160.0}, 2.852688},
{{160.0, 170.0}, 2.827547},
{{160.0, 180.0}, 2.818931},
{{160.0, 190.0}, 2.826640},
{{160.0, 200.0}, 2.851483},
{{170.0, 160.0}, 2.861634},
{{170.0, 170.0}, 2.832750},
{{170.0, 180.0}, 2.822240},
{{170.0, 190.0}, 2.830275},
{{170.0, 200.0}, 2.858395},
{{180.0, 160.0}, 2.862344},
{{180.0, 170.0}, 2.831671},
{{180.0, 180.0}, 2.820786},
{{180.0, 190.0}, 2.831775},
{{180.0, 200.0}, 2.862605},
{{190.0, 160.0}, 2.857940},
{{190.0, 170.0}, 2.830020},
{{190.0, 180.0}, 2.822137},
{{190.0, 190.0}, 2.832657},
{{190.0, 200.0}, 2.861574},
{{200.0, 160.0}, 2.850865},
{{200.0, 170.0}, 2.826201},
{{200.0, 180.0}, 2.818547},
{{200.0, 190.0}, 2.827127},
{{200.0, 200.0}, 2.852228}
}]
s1=Function[{a,b},surf[a,b]]
da=Function[{a,b},D[s1[a,b],a]]
Plot3D[da[a, b], {a, 175.0, 185.0}, {b, 175.0, 185.0}]
When running this input Mathematica gives the error:
General::ivar: 175.00071499999999` is not a valid variable
Any help will be greatly appreciated !
Many thanks!
Evgeniy