Subversion Repositories lagranto.icon

Rev

Go to most recent revision | Details | Last modification | View Log | RSS feed

Rev Author Line No. Line
3 michaesp 1 
.TH tracal
2 
.SH NAME
3 
.B tracal - simple calculations with trajectory files
4 
.SH SYNOPSIS
5 
.B tracal
6 
.I inpfile
7 
.I outfile
8 
.I expression
9 
.SH DESCRIPTION
10 
Simple calculation on the input trajectory file
11 
.I inpfile
12 
; the output is written to the output trajectory file
13 
.I outfile
14 
and the expression for the calculation is given in
15 
.I expression.
16 
.SH PARAMETERS
17 
.TP 15
18 
.I inpfile
19 
input trajectory file
20 
.TP 15
21 
.I outfile
22 
output trajectory file (can be the same as inpfile).
23 
.TP 15
24 
.I expression
25 
arithmetic expression, e.g. 'DIFF=PS-p' to get difference between surface pressure (PS)  and the pressure height of the trajectory (p). Note that the variable names must exactly match to the column names in the trajectory file.
26 
The mathematical expression can contain previously defined variables, numbers (e.g., 1.5 or 1.5e-6), arithmetic operators (+, -, *, /, ^), and a number of mathematical functions (sin, cos, tan, sqrt, exp, log, ln, abs, ang, real, imag, conjg, complex). The expression can also use nested levels of parentheses for grouping. There are two predefined variables that are available to the user — the constant pi=3.14159265358979 and the imaginary unit i.
27 
.SH EXAMPLES
28 
.TP 5
29 
.B [1] tracal inp out 'agl=z-zb'
30 
caculates the difference between air parcel height (z) and surface height (zb). The result is saved in an new column (agl).
31 
.SH AUTHOR
32 
Written by Michael Sprenger and Heini Wernli (August 2012); the evaluation of the arithmetic expression is based on the string manipulation routines by 'Dr. George Benthien' (http://gbenthien.net/index.html).
33 
 
34