#yell "DEBUG:tune_p:$tune_p";
#yell "DEBUG:tune_i:$tune_i";
error="$(try echo "$var_sp - $var_pv" | bc -l)";
#yell "DEBUG:error:$error";
#yell "DEBUG:tune_p:$tune_p";
#yell "DEBUG:tune_i:$tune_i";
error="$(try echo "$var_sp - $var_pv" | bc -l)";
#yell "DEBUG:error:$error";