Mathematical interpolation (2D)

1

Dear Experts,
is is possible to make interpolation to the values got from excel table?
Example:
image
inputs A=0.22
B=0.15
Result: 11.04

2

Yes this could work. Find the first value along the axis which your input is greater than. Then find the number above that. Then parameterize the space between to get the interpolation on the axis. Do this for both axis, and finally map the axis interpolation to the values in the chart.

3

Hi,
SciPy library has an interesting sub-package for this
https://docs.scipy.org/doc/scipy/reference/interpolate.html

an example with interp2d (linear kind) , there are several methods and options

image
image1464×545 97.3 KB 

import sys
import clr
import System
import re
clr.AddReference('ProtoGeometry')
from Autodesk.DesignScript.Geometry import *

reDir = System.IO.DirectoryInfo(re.__file__)
path_py3_lib = reDir.Parent.Parent.FullName
sys.path.append(path_py3_lib + r'\Lib\site-packages')

import openpyxl
import pandas as pd
import numpy as np
from scipy.interpolate import griddata, interp2d


df = pd.read_excel(IN[0], index_col=0)
x = df.columns # A
y = df.index # B
z = df.values

f = interp2d(x, y, z, kind='linear')
interpolate = f(x = 0.22, y = 0.15)
OUT = interpolate

visualization of the interpolated point on the grid

plot interpolated point

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