Issues in storing data from file sink in gnu radio

i’m trying to store some fft data in a csv file format using the File Sink block. The OS is linux, and therefore i’m using the LibreOffice Calc version( in which i have selected the csv format to store the data in. But after running the flowgraph, the data gets stored as Unicode or ASCII/US characters in the file(These type of options are available for the character set) , instead of the expected float values. I do not understand if this data is just garbage values or actually makes sense, but i require float values for further processing. Here is a screenshot:

What could be wrong? It would be great if someone could help out.