tchart: A program to generate temperature charts.

Usage: tchart filename{.html} [options]

If the -o option is not specified then tchart generates a
file with the same name as the HTML input file but with a
.BMP filetype.

The chart is landscape 7.5 inches by 10.0 inches. The
default DPI is 150.

Multiple processing steps may be specified. Processing is
done in this order: averaging, median filtering, polynomial
fitting, FFT filtering.

Options:

-average radius

Smooths the input data by replacing each value with the
average of the values plus and minus the specified radius
from the center value. A radius of 1 means that three points
are averaged. A radius of 2 means that five points are
averaged.

-debug

If the -fft option is specified then the -debug option logs
the FFT coefficients to file tchart.txt.

-dpi n

Sets the chart's resolution. The default DPI is 150.

-fft nterms

Smooths the input data by calculating a Fast Fourier
Transform (FFT), zeroing high frequency terms, and
calculating the inverse FFT. The "nterms" parameter
specifies the number of low frequency terms to keep. A value
of 1 keeps just the first term which is the average value. A
value of 2 keeps the first two terms which are the average
value plus the full-width wave function.

-help

Displays this help message.

-hi temp
-lo temp

By default tchart calculates the Y axis temperature range
automatically. The Y axis high and low temperatures can be
be specified with the -hi and -lo options. The high and low
temperatures are integer values.

-lsq nterms

Smooths the input data by calculating an optimal
least-squares polynomial equation. Parameter "nterms" is the
number of polynomial terms. A value of 3 fits a three term
parabola with equation v = ax^2 + bx + c. A value of 4 fits
four term curve with equation v = ax^3 + bx^2 + cx + d.

-median radius

Smooths the input data by replacing each value with the
median of the values plus and minus the specified radius
from the center value. A radius of 1 means that three points
are sorted to determine the median. A radius of 2 means that
five points are sorted.

-o filename{.bmp}

Specifies the output filename. The default output filename
is the input filename with a .BMP filetype.

-q

Quiet mode. Don't explain what's going on.