Interpolation function error: Part doesn't exist

Questions
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1

Problem:
I import a list of values (POCinput) and transform it into an “InterpolationFunction” to be used as initial condition:

INIPOCn = 
POC[x, 0] == 
Interpolation[Transpose[List[Table[x, {x, 0, L}], << POCinput]]]

POC[x,0]==InterpolatingFunction[Domain: {{0.,100.}}
Output: scalar

When using this input in “NDSolve” I receive the following error messages:

Part::partw: Part 4 of POC[x,0]==InterpolatingFunction[{{0.,100.}},{5,7,0,{101},{4},0,0,0,0,Automatic,<<3>>},{{0.,1.,2.,3.,4.,5.,6.,7.,8.,9.,<<91>>}},{Developer`PackedArrayForm,{0,1,2,3,4,5,6,7,8,9,<<92>>},0.00838574,0.00834735,0.0083137,0.00828387,0.00825718,0.00823311,0.00821125,0.00819128,0.00817292,0.00815598,<<91>>}},{Automatic}] does not exist.

NDSolve::deqn: Equation or list of equations expected instead of (POC[x,0]==InterpolatingFunction[{{0.,100.}},{5,7,0,{101},{4},0,0,0,0,Automatic,<<3>>},{{0.,1.,2.,3.,4.,5.,6.,7.,8.,9.,<<91>>}},{Developer`PackedArrayForm,{0,1,2,3,4,5,6,7,8,9,<<92>>},{0.00838574,0.00834735,0.0083137,0.00828387,0.00825718,0.00823311,0.00821125,0.00819128,0.00817292,0.00815598,<<91>>}},{Automatic}])[[4,3]] in the first argument {2.65 (0.45 -0.1 E^(-x/20000)) (POC^(0,1))[x,t]==-((2.65 (0.45 -0.1 E^Times[<<2>>]) POC[x,t])/(1000. +100. x)^1.4)-0.011925 (POC^(1,0))[x,t],0.011925 POC[0,t]==0.0001,(POC[x,0]==InterpolatingFunction[{{0.,100.}},{5,7,0,{101},{4},0,0,0,0,Automatic,<<3>>},{{0.,1.,2.,3.,4.,5.,6.,7.,8.,9.,<<91>>}},{Developer`PackedArrayForm,{0,1,2,3,4,5,6,7,8,9,<<92>>},{0.00838574,0.00834735,0.0083137,0.00828387,0.00825718,0.00823311,0.00821125,0.00819128,0.00817292,0.00815598,<<91>>}},{Automatic}])[[4,3]],<<5>>,Cl[0,t]==555.,Li[0,t]==0.024,<<9>>}.

Any idea what is wrong here? The input should be a scalar function, which is the case.

Thanks for suggestions…

2

Unlikely that anyone can help unless you show the code that calls NSolve.

3

Thank you! Likely right, but the code is very long. I’ll try to simplfy the problem and come back..