The Yagi-Uda project's programme  yagi

yagi calculates the antenna currents of a file containing an  antenna specification, that has first be written into the appropriate form using first or input. It then writes the values of the antenna currents to a file with the extension .out.

The manual page  yagi.1  describes all the options of yagi. The manual page yagi.5 describes the binary file format written by yagi. However, it is better to read this page before looking at the man pages.

In the description on the programme first, there is an example of a 5 element Yagi-Uda antenna being created and saved in a file called example1. This will be analysed with yagi now
 

parrot /export/home/drkirkby/yagiuda-1.18/src % yagi example1
yagi compleated   0.0% f=144000000.000000 MHz
yagi compleated   5.0% f=144100000.000000 MHz
yagi compleated  10.0% f=144200000.000000 MHz
yagi compleated  15.0% f=144300000.000000 MHz
yagi compleated  20.0% f=144400000.000000 MHz
yagi compleated  25.0% f=144500000.000000 MHz
yagi compleated  30.0% f=144600000.000000 MHz
yagi compleated  35.0% f=144700000.000000 MHz
yagi compleated  40.0% f=144800000.000000 MHz
yagi compleated  45.0% f=144900000.000000 MHz
yagi compleated  50.0% f=145000000.000000 MHz
yagi compleated  55.0% f=145100000.000000 MHz
yagi compleated  60.0% f=145200000.000000 MHz
yagi compleated  65.0% f=145300000.000000 MHz
yagi compleated  70.0% f=145400000.000000 MHz
yagi compleated  75.0% f=145500000.000000 MHz
yagi compleated  80.0% f=145600000.000000 MHz
yagi compleated  85.0% f=145700000.000000 MHz
yagi compleated  90.0% f=145800000.000000 MHz
yagi compleated  95.0% f=145900000.000000 MHz
yagi compleated 100.0% f=146000000.000000 MHz

That is it - the antenna currents have been calculated and saved to a file. The results are in a binary file called example1.out. In order to see how well the antenna performs (gain, FB ratio etc.) we must use the programme output.  For more information on the options to yagi, see the manual page  yagi.1