Plotting two data sets with different time intervals, where time is not wanted on the axis

Hello,

I'm trying to plot graph of two data set, solar irradiance (SI) vs. temperature. (T) I would like solar irradiance on the X-axis and temperature on the Y-axis. My problem is the way the data is recorded means that solar irradiance is measured in intervals of 1 minute, and the temperature is measured in intervals of 5 seconds. Therefore if I plot them as is I end up with SI 1 minute vs T 5 seconds, SI 2 minute vs T 10 seconds etc.

The data set is far too big to manually pick the minute intervals for temperature and plot them against solar irradiance. Is there a way I can plot them correctly? Possibly one that picks the n'th values, being every minute for temperature?

Thanks

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Thanks for the reply! This is the first chance I've had to check back here. I'll give it a try and see how I get on thanks.