When making circuit I am constantly using resistors matched by some ratio in some form or another, whether that be in an op-amp multiplier or a simple resisistive divider. When you have strange ratios such 5.95 I required for the LM399 testbench it can be hard to find standard values with a common ratio. There are online tools to tell you the best mixture of standard resistors to create a required resistance but none that I could find that will find a ratio or use a single resistor. This is much more use for me as I would much rather use a single resistor in my design than over-complicate a design with series and parallel combinations and I am almost always looking for ratios not specific resistances. To do this I have made an installable console command that will allow you to find the best ratio. You can get it from GitHub Here and install simply by:
./configure make make install
ResRat is a simple interface allowing for input of a ratio which compares all common resistor series to see if there is a resistor ratio that matches and if not reports back the closest in each series as seen below.
Figure 1: Resrat simple use.
ResRat has two command line arguments if you'd like to skip the input step for speed and instead pass it in the command or choose a specific resistor series.
resrat -r *resistor ratio* -e *resistor series*
Figure 2: Resrat command line arguments use.