Problems about using command pfsstat

[Jinxue Liu]

Hi everyone,

I have encountered errors on using command pfssstat. Before installing pfstools, I have already installed the Octave (version 4.2.2) and the signal packages (version 1.3.2 ) successfully.
And I have loaded the package by using pkg load signal command in Octave prompt. Then, I have installed pfstools (version 2.1.0) and the installation went smoothly witout any
errors. All the installations were operated on my ubuntu 16.04.4 virtual machine.

When I used the following commands:

$ pfsinexr 507.exr | pfsstat

The terminal showed:

warning: the 'gausswin' function belongs to the signal package from Octave Forgewhich you have installed but not loaded. 
To load the package, run 'pkg load signal' from the Octave prompt.

However I have already loaded the signal package after I installed the package.

Can anyone suggest what I might be doing wrong here. 

Thanks in advance !!