Undefined function 'trend' for input arguments of type 'double'

Hai everyone, i facing some problem with the script. I'm using trend function but had an error like this

Undefined function 'trend' for input arguments of type 'double'.

Error in script_msl_v2 (line 14)

ud=trend(data{:,4:end},[],2,'omitnan');

with this script

clear;
clc;
format longG;

f = dir('D:/full_Data_Cryosat_c2p0004.txt');
A=1:length(f);
D = f(A).name;

Insufficient number of outputs from right hand side of equal sign to satisfy assignment.

ff=D(:,19:25)

data=readtable(D,'HeaderLines',0);

rata2=mean(data{:,4:end},2,'omitnan');
standar_deviation=std(data{:,4:end},[],2,'omitnan');
ud=trend(data{:,4:end},[],2,'omitnan');

ref=data{:,1};
lat=data{:,2};
lon=data{:,3};
msl=[ref lat lon rata2 standar_deviation]

file_name_msl=['msl_' ff '.txt']
dlmwrite(file_name_msl, rata2, 'delimiter', '\t');
file_name_data=['data_msl_' ff '.txt']
dlmwrite(file_name_data, msl, 'delimiter', '\t','precision',10);

What should i do to solve that?

Thanks for helping

Answer 1

[Dave B]

If you're trying to use a function you got from elsewhere (e.g. downloaded from file exchange) you likely need to add the directory containing that function to the MATLAB path. For an easy graphical interface for managing the path, just run: pathtool

If you're expecting trend to be a builtin function in MATLAB, I think it's not...what were you expecting it to do?

which trend

'trend' not found.