Retain previous slider value in mel

[mostly_human]

I am working with blendshapes and expressions and I need a way to know if the last slider value was higher or lower than what it was just changed to, basically if the slider is being raised or lowered in value.  Im not really sure how I would do that in an expression. Any help is sincerely appreciated!

[stuzzz]

hello,

What about creating a custom attribute to a node and let the expression set the ouput result to this attribute.

the next time the expression will be called, it will query that custom attribute value and will calculate a delta with your old and new value. That delta will tell you weither it's been lowered or not.

For what reason you need an expression?