The following is from a post I did at the SFTE Forum and considered to put it also here for future reference:
I have tried various packages for data analysis/reduction. Below my opinion on some of the most common ones.
MATLAB is used in many flight test establishment and is one of the standard engineering tools. Falls under the category of programming languages.
Pros: Very common engineering tool can be found in most companies and most new engineers are familiar with it. The wide variety of commands and libraries can perform any data reduction process from basic to very advanced. Array manipulations, vector analysis, time and frequency domain analysis, filtering, statistics, even system identification. Figures produced are decent, maybe not the most user friendly, but a lot of options. If I had to select only one tool, it would be MATLAB.
Cons: Can be pricy. You don’t have direct view of the data reduction steps as in a spreadsheet based package. For basic data reduction of small databases it can be an overkill.
Standard tool found in vast majority of computers. Representative of spreadsheet based packages.
Pros: Everyone has Excel and is up to some point familiar with using it. Very friendly spreadsheet based, can add colors, comments, paste images and figures and make a data reduction sheet very explanatory. Great to use when introducing new professionals/students to data reduction. You can monitor each reduction step and its effect on the data just by looking at the spreadsheet and plotting is easy. Ideal for basic to medium data reduction of limited amount of data.
Cons: It has limits in how advanced it can go. Cannot easily handle very big storage of data. Cannot be integrated easily (according to my knowledge) with other tools to form a part of a greater data reduction process.
Special and interesting tool that you typeset standard mathematical notation instead of programming code.
Pros: You can see the formulas in mathematical notation and edit accordingly. You need not to worry about units conversions. It is self-reporting, meaning that if you setup your file in a nice form, you can add text and shapes and it will save out a report-like document for you. Can go more advanced than Excel easily. The learning curve is said to be less steep than MATLAB, but I cannot confirm as I was a MATLAB user for many years when I was introduced to MathCAD.
Cons: Not very common tool. If you need to share your work in MathCAD, you will not find a lot of individuals using it.
Other tools can also be used for effective data reductions, most of which resemble the one above some of which are open source and free. Many engineers have been using other spreadsheet based tools for data analysis and plotting or programming languages which have similar characteristics to the ones mentioned above. There are also some dedicated flight test data reduction tools like Symvionics IADS. I have used this package mostly in telemetry rooms and I am aware of its data reduction capabilities which can also be customized, however I have not used it (yet) for data reduction purposes.
Personally I use both MATLAB and Excel depending on the problem each time.