Data Master 2000 includes several basic numeric analysis operations
as well as powerful data processing tools. By default these commands available
in the Process menu of the main window. Data analysis
operations act on the selected range of data of plot or worksheet viewers of the
active data window. If no correct data range
available (some operations require more than two lines!) these commands may be
The most of operations require a range of worksheet lines, and X, Y columns.
If worksheet viewer is focused, operation will work with the selection of
worksheet, otherwise it will use data range from the current plot serie
(worksheet reference, first and last line, X and Y columns). Some
operations work only with plot serie, while others are disabled until worksheet
viewer is not focused.
Differentiation requires both X and Y columns and has two modes:
3-point parabolic interpolation and best-fit smoothing (see below for more
details about smoothing). Use first method for for curves with sharp
features and little noise level. Otherwise you should use smoothing because
usually differentiation extremely increases noise level. This operation adds
new column to the end of every worksheet line.
Integration performs numeric integration of the given Y(X) function
using well-known trapezoid method. Integration result always starts from
zero. Like differentiation, this function requires both X and Y columns and
adds new column to the end of every worksheet line.
Smoothing used to reduce noise level. This operation is especially
necessary for data files produced by the measurement facilities. For every
point Smoothing builds "best-fit" line Ybf=a*X+b in the
defined vicinity of current point and then assumes Ysmooth=Ybf(X).
This procedure allows easily obtain derivative: in this case you should take
"a" coefficient calculated for given point.
Calculation should be used to calculate the result of arbitrary
symbolic expression for every worksheet line in the selected data range. See
expression syntax for more details about available
operators, functions and parameters names. If Ins/Owr flag (indicated in the
status line of the main window) set to
"Ins" state, this operation adds the result to the end of
worksheet line like previous operations. Otherwise, Y column will be
replaced by the result of calculation.
Interpolation command performs linear interpolation of the given
Y(X) data with fixed X step. Data range for this operation must be sorted
from minimum to maximum (use Edit|Sort command
before interpolation). This command is convenient to create equal-step
sequences of numbers: just input first and last range and then perform
interpolation. Unlike previous commands, the result of interpolation (Y(X)
function) added to the end of worksheet.
Keep in mind that all abovementioned operations simply
ignore plot selection since they are non-local, i.e. require several adjacent
points to calculate the result. If they would use selection, this requirement
may be violated.
In addition to the basic numeric operations discussed above, Process menu
contains several powerful data processing tools that include special complex
dialog procedures (click links for more information):
Digitizer - digitize any graph
image in the bitmap format;
Linear fitting - start linear
fitting session and find "best fit" parameters;
perform nonlinear (Levenberg-Marquardt) fitting with arbitrary expression;
Lorentzian fitting - NLSF fitting with
predefined Lorentzian equation and initial parameter evaluation.
It should be specially remarked that DM2000 is programmable
environment. With additional scripts
user interface you may easily extend basic set of numeric operations and
create powerful batch processing functions. See sample files supplied with
DM2000 (in the samples.zip archive) for examples.