diff options
Diffstat (limited to 'Windows/spice/share/ngspice/scripts/spectrum')
| -rw-r--r-- | Windows/spice/share/ngspice/scripts/spectrum | 165 |
1 files changed, 0 insertions, 165 deletions
diff --git a/Windows/spice/share/ngspice/scripts/spectrum b/Windows/spice/share/ngspice/scripts/spectrum deleted file mode 100644 index 3e394432..00000000 --- a/Windows/spice/share/ngspice/scripts/spectrum +++ /dev/null @@ -1,165 +0,0 @@ -* Fourier Series Function for SPICE -* This script is offered here for learning purposes, even if it is outdated -* and superseeded by the spec function and especially by the much faster fft function. -* You may use this script in conjunction with e.g. a ringoscillator output (see -* the ngspice manual, chapter 17). - -.control - begin - -* Variable argc delivers the number of command line parameters given by the user -* after the 'spectrum' command - if ($argc lt 4) - echo Error: Too few arguments. - echo ' 'Spectrum produces a plot containing a fourier series transformation of - echo ' 'the specified vectors - echo usage: spectrum startfreq stop step vec [[vec] ...] - goto bottom - end - -* Check if vectors 'time' and any input vector(s) are available -* argv[n] delivers the command line entries after the 'spectrum' command, -* starting with argv[1]. $argv[4-len] delivers the value of all tokens, -* starting with postion 4 till the end of the command line - if ( time eq time ) - foreach vec $argv[4-len] - if ( $vec eq $vec ) - else - goto bottom - end - end - else - echo ' 'Spectrum can not work without a time vector from a transient analysis. - goto bottom - end - - * generate a new plot entitled 'scratch', which will hold intermediate - * results and will be discarded after their evaluation. - set dt=$curplot - set title=$curplottitle - set curplot=new - set scratch=$curplot - - * A vector 'span' is created in the 'scratch' plot to hold the time difference - * of the transient simulation. {$dt}.time allows to access the 'time' vector - * from the dt plot (which is normally named 'tranx' with x a consecutoive - * integer number, depending on the amount of transient simulations already run - * in the present job. - let span={$dt}.time[length({$dt}.time)-1]-{$dt}.time[0] - -* Calculate the number of steps in all of the spectra to be evaluated below - if ($argv[3] gt 0.999/span) - let fpoints= ( $argv[2] - $argv[1] ) / $argv[3] +1 - if (fpoints < 2) - echo frequency start stop or step not correctly specified - goto reset - end - else - echo Error: time span is not long enough for a step frequency of $argv[3] Hz - goto reset - end - let lent = length({$dt}.time) - set lent = "$&lent" - let nyquist = {$lent}/2/span - if ($argv[2] gt nyquist) - echo Error: The nyquist limit is exceeded, try a frequency less than "$&nyquist" Hz - goto reset - end - set fpoints="$&fpoints" - - * generate a new plot to hold the spectra - set curplot=new - set spec=$curplot - set curplottitle=$title - set curplotname='Spectrum Analysis' - -* argv[3] is the third agrgument from the input line -* spectrum 1 1000MEG 10MEG v(out25) -* that is the delta frequency -* The fcn vector(n) creates a vector of length n, its elements have -* the values 0, 1, 2, 3, ..., n-2, n-1. Each element then is multiplied -* with the frequency step value. - let frequency=vector( $fpoints )*$argv[3] - -* Add an frequency offset to each element of vector 'frequency' -* to suppress the (typically) large dc component. - dowhile frequency[1] < ( $argv[1] + 1e-9 ) - let frequency = frequency + $argv[3] - end - -* For each input vector given on the command line, -* create a new vector for complex numbers - foreach vec $argv[4-len] - let $vec = vector( $fpoints ) + j(vector( $fpoints )) - reshape $vec [{$fpoints}] - end - -* $scratch is a plot for intermediate results, will be destroyed during cleanup -* $dt is the plot with the original data -* $spec is a plot for storing the spectrum - set curplot=$scratch - - * some test - let npers=1 - let test = span-2/$argv[3] + 1e-9 - while test > 0 - let npers = npers + 1 - let test = test-1/$argv[3] - end - - * Do the spectrum calculations - let ircle = 2*pi*max(-1,({$dt}.time-{$dt}.time[{$lent}-1])*{$argv[3]}/npers) - let win = 1 - cos(ircle) - let ircle = npers*ircle - let circle = ircle * ({$spec}.frequency[0]/$argv[3] - 1) - let k=vector( $fpoints ) - foreach k $&k - let circle = circle + ircle - foreach vec $argv[4-len] - let tmp = win*{$dt}.{$vec} - let {$spec}.{$vec}[{$k}] = 2*(mean(cos(circle)*tmp),mean(sin(circle)*tmp)) - end - end - -* plot (and write) the generated spectrum - set curplot = $spec - settype frequency frequency - foreach vec $argv[4-len] - let spectrum = mag({$vec}) - plot spectrum - write specout.out spectrum - end - -* If you have an oscillator, fimd its frequency -* as maximum of vector spectrum or goto end (uncomment next line) -* goto cleanup - set curplot=$scratch - let counter = 0 - let contents = 0 - let freqmax = 0 - let spectrum = {$spec}.spectrum - - foreach spectrum $&spectrum - if counter > 4 - if ( contents < $spectrum ) - let contents = $spectrum - set count = "$&counter" - let freqmax = {$spec}.frequency[{$count}] - end - end - let counter = counter + 1 - end - - echo - echo Osc. frequency at "$&freqmax" Hz - echo - goto cleanup - - label reset - set curplot=$dt - label cleanup - destroy $scratch - unset fpoints dt scratch spec vec k title lent - label bottom - - end |