Interpolate a parammeter which is not a function of X, Y , Z . Each point ( X, Y , Z ) has a measured parameter which indicates noise at that specific point .

I have a shapefile (Points) which has the following attributes ( X,Y,Z,Dag) . Each point of my shape has a coordinate ( X,Y,Z) and also a measured parameter which indicates noise at that specific point . My problem is that Dag ( measured noise ) is not a function of X,Y,Z . To make it more clear , I should say that we are analayzing the behaviour of noise in 3 dimension , so we should interpolate noise on a defined coordinate system . In other words , because my forth parameter is not a function of X, Y , Z I can not use the triscatterinterp , griddata3 for interpolation .

I wrote this code : clc clear all format long g

% input data A=xlsread('hamidReza.xlsx');

% nonuniformly spaced vectors X=A(:,11); Y=A(:,12); Z=A(:,4); dag=A(:,6); avond=A(:,7); nacht=A(:,8);

% uniformly spaced vectors xi=539900:6.7:540570; yi=3955970:7.9:3956760; zi=3:0.51:54;

[XI,YI,ZI]=meshgrid(xi,yi,zi);

% interpolation for DAG DAG= TriScatteredInterp(X,Y,Z,dag);

% interpolation for AVOND AVOND= TriScatteredInterp(X,Y,Z,avond);

% interpolation for NACHT NACHT= TriScatteredInterp(X,Y,Z,nacht);

There is error in TriScatteredInterp(X,Y,Z,dag); I do not know how I can deal with this problem ...