Dealing with such data has been rather neglected by programmers. There are, however, several freeware, and shareware graphing programs that take lots of sets of numbers. They can be downloaded from the net. On the subject of data points there is one peculiar hazard of interpreting the intermittent data that comes from digital data loggers, in comparison with the continuous trace from the thermohygrograph. It is possible to get quite wrong graphs in air conditioned rooms.
Most air conditioners switch between heating and cooling and wetting and drying, at set points.
The continuous graph looks like the purple zigzag. Some data loggers can be told to measure more frequently and then average the result before memorising it. This also can give misleading curves by smoothing out variations that are often useful in diagnosis. Useful diagnostic procedures Translating the values for RH and T into dew point or vapour pressure will reveal if the inside air is just outside air warmed up, or cooled. Any excess of water indicates rising damp, leaky walls or roof, a simmering coffee maker, or lots of people.