Economic index reconstruction using Recurve
The problem: a certain data is publicly available only for the last ten years in the form of data table.
I'd like to complete it with the largest time frame's data.
But: there are many charts with "all time" data on the Web.
The solution: use Recurve!
This is done in 3 easy steps (OK, after 3 preliminary steps ๐):
-2) Download and install GNAT from here.
-1) Download GID (Generic Image Decoder) from here or here, or get it as a crate from Alire (crate description here)
0) Build the GID tools (Windows: double-click "build.cmd" or command-line: "gprbuild -p -P gid" or Alire: "alr get gid", then "alr run" (details in the doc)).
1) Open the "test" directory.
2) Windows and probably others: drag-&-drop your chart image on recurve[.exe], or command-line: "[./]recurve pic.ext"
3) Open the .csv in your favorite spreadsheet app, chart the recurve data for comparing with the original chart image.
Now, we can see the various data reconstruction steps. Starting point:
- Turn x values from pixels into dates, pick correct curves at the ends (the moving average 20 days in the chart happened to have the same colour as the values).
- De-logarithm-ize the y values, have index points instead of pixels.
- Switch to the actual data since March 2011.
Done!