Re: ListInterpolation
- To: mathgroup at smc.vnet.net
- Subject: [mg58342] Re: ListInterpolation
- From: "Valeri Astanoff" <astanoff at yahoo.fr>
- Date: Tue, 28 Jun 2005 21:56:41 -0400 (EDT)
- References: <d9r4tv$55q$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Stephane,
In your example, seems to me that if there are
4 occcurrences of x and 2 of y, then the data
should be a {4,2} list (which is not the case,
so your data have to be transposed).
If I was you, in such a case of explicit values
of the variables, I would first "regularize"
the data to get an evenly spaced grid, before
using ListInterpolation.
An example of what you could do :
In[1]:=data1={{1, 1.3, 2.5, 5},{1, 2, 3, 4}}//Transpose
Out[1]={{1,1},{1.3,2},{2.5,3},{5,4}}
In[2]:=data2={{1, 1.3, 2.5, 5},{5, 6, 7, 8}}//Transpose
Out[2]={{1,5},{1.3,6},{2.5,7},{5,8}}
In[3]:=f1=Interpolation[data1];
In[4]:=f2=Interpolation[data2];
In[5]:=gridData={Table[f1[x],{x,1,5,4/3}],
Table[f2[x],{x,1,5,4/3}]}//Transpose
Out[5]={{1.,5.},{3.05919,7.05919},{2.22269,6.22269},{4.,8.}}
In[6]:=res = ListInterpolation[gridData, {{1, 5}, {0.5, 1.3}}] ;
>From In[6]:=
ListInterpolation::inhr:Requested order is too high; order has been
reduced to {3, 1}
In[7]:=res[1,0.5]
Out[7]=1.
In[8]:=res[5,1.3]
Out[8]=8.
In[9]:=res[2,1.1]
Out[9]=6.03108
Valeri