QSoas tips and tricks: permanently storing meta-data

It is one thing to acquire and process data, but the data themselves are most often useless without the context, the conditions in which the experiments were made. These additional informations can be called meta-data. In a previous post, we have already described how one can set meta-data to data that are already loaded, and how one can make use of them.

QSoas is already able to figure out some meta-data in the case of electrochemical data, most notably in the case of files acquired by GPES, ECLab or CHI potentiostats. However, only a small number of constructors are supported as of now^[1], and there are a number of experimental details that the software is never going to be able to figure out for you, such as the pH, the sample, what you were doing...

The new version of QSoas provides a means to permanently store meta-data for experimental data files:

QSoas> record-meta pH 7 file.dat

This command uses record-meta to permanently store the information pH = 7 for the file file.dat. Any time QSoas loads the file again, either today or in one year, the meta-data will contain the value 7 for the field pH. Behind the scenes, QSoas creates a single small file, file.dat.qsm, in which the meta-data are stored (in the form of a JSON dictionnary).

You can set the same meta-data to many files in one go, using wildcards (see load for more information). For instance, to set the pH=7 meta-data to all the .dat files in the current directory, you can use:

QSoas> record-meta pH 7 *.dat

You can only set one meta-data for each call to record-meta, but you can use it as many times as you like.

Finally, you can use the /for-which option to load or browse to select only the files which have the meta you need:

QSoas> browse /for-which=$meta.pH<=7

This command browses the files in the current directory, showing only the ones that have a pH meta-data which is 7 or below.

[1] I'm always ready to implement the parsing of other file formats that could be useful for you. If you need parsing of special files, please contact me, sending the given files and the meta-data you'd expect to find in those.

About QSoas

QSoas is a powerful open source data analysis program that focuses on flexibility and powerful fitting capacities. It is released under the GNU General Public License. It is described in Fourmond, Anal. Chem., 2016, 88 (10), pp 5050–5052. Current version is 3.0. You can download its source code there (or clone from the GitHub repository) and compile it yourself, or buy precompiled versions for MacOS and Windows there.