Perple_X Tab File Format
In the 6.6.6 version of Perple_X, most output files written by WERAMI, and
property tables generated by FRENDLY and FLUIDS, are written as 1- or 2-dimensional
tables. These tables have the general format described below and are indicated
by the file type suffix ".tab".
2d Tables
In 2d tables, the columns correspond to properties tabulated as a function of
two independent variables at regular intervals (e.g., mineral composition as a
function of pressure and temperature). The columns of a 2d table can be
contoured or viewed as a 3d surface as a function of its independent variables
with PSTABLE (Perple_X), PYWERAMI (petrol.natur.cuni.cz/~ondro/pywerami:home),
or Perple_X_plot (MatLab, perplex.ethz.ch/perplex/ibm_and_mac_archives/...
MatLab_scripts_6.6.6.zip). Alternatively, if the header section of the tab file
is deleted, the data can be imported into spreadsheet programs (e.g., Excel).
Note that if you intend to import a table into a spreadsheet program it is
essential that you set the keyword spreadsheet = T in perplex_option.dat. This
option instructs WERAMI to write the independent variables in the first columns
of the table. The MatLab script pt_2_vs changes the independent variables of 2d
tables, e.g., if a table has been computed as a function of pressure and
temperature, pt_2_vs can be used to convert the table to a table as a function
of volume and entropy.
1d Tables
In 1d tables, the columns correspond to properties tabulated as a function of
one independent variable (e.g., mineral composition as a function of pressure
and temperature along a geotherm). In contrast to 2d tables, the independent
variable need not vary by a regular increment. All Perple_X programs and
scripts assume irregular spacing of the independent variable and therefore
output a column(s) containing the independent variable(s) of the calculation
as well as the dependent properties. In this case the header information is
largely superfluous and the number of variables is the number of columns and
the number of rows in the table is the number or records in the file less the
number of records in the header (see format details below). Any two columns of
a 1d table can be plotted against each other with PSTABLE (Perple_X) or
Perple_X_plot (MatLab, perplex.ethz.ch/perplex/ibm_and_mac_archives/...
MatLab_scripts_6.6.6.zip). Alternatively, if the header section of the tab file
is deleted, the data can be imported into spreadsheet programs (e.g., Excel).
Tab Format Details
Line 1 - the tag "|6.6.6", included in case of future format changes
Line 2 - title
Line 3 - n - number of independent variables
For independent variable j = 1 -> n
Line 4 + (j-1)*4 - name of jth independent variable
Line 5 + (j-1)*4 - v0(i) - minimum value of jth independent variable
Line 6 + (j-1)*4 - dv(i) - increment for jth independent variable
Line 7 + (j-1)*4 - inc(i) - 1 + number of increments for jth independent variable
Line 8 + 4n - m - number of dependent properties
Line 9 + 4n - names of the m dependent properties
For i=1,inc(n), j=1,inc(n-1), ..., l=1,inc(1) (inner index changing fastest) lines
consisting of the m dependent properties at v(1) = v0(1) + (i-1)*dv(1),
v(2) = v0(2) + (j-1)*dv(2),..., v(n) = v0(n) + (l-1)*dv(n)
This format implies 5n+1 header lines and inc(1)*inc(2)...*inc(n) data records,
each data record consisting of m entries.
Reading Tab Files in Matlab
The MatLab function script get_perple_x_file reads Perple_X tab files into Matlab.