How do I remove a known trendline from data?

Hi,

I have determined that the data I have captured has a systematic linear trend with gradient 0.003. Is there a straightforward way to detrend my data from this known trend. I don't want to use the function detrend because it might remove a trend specific to that acquisition in addition to the known systematic trend.

Answer 1

[KSSV]

Use polyfit, fit a striaght line and subtract this from the data.

[Gail Distefano]

Many thanks for your answer. I'm afraid I don't understand what you mean.I don't want to fit a straight line to my data. I want to remove a slope of 0.003 from the signal in the attached figure.