Replacing values in a column with a conditional statement.

Hi I am new to matlab and not so familiar with conditional statemet. In the data below, I want to change NEE value based on a condition: Accept the NEE value if NEE_fc == 0 or 1 and substitute NEE values with -9999 if NEE_fc is > 0 or 1. Help will be much appreciated.

Data looks like this

Date NEE NEE_fc

2018 -0.2 0

2018 0.2 1

2018 0.3 2

2018 -0.002 3

Desired result

Date NEE NEE_fc

2018 -0.2 0

2018 0.2 1

2018 -9999 2

2018 -9999 3

Answer 1

[Walter Roberson]

mask = NNE_fc > 1;
NNE(mask) = -9999;