Building trends diagram to SVG, which may be builtin next to the XHTML-document, for specified period of the time [(end-size)...end] and from the sources srcs.

The diagram forming code is based on code of the primitive "Diagram" of the visualisers, and which was quite simply migrated from C++ to the JavaLikeCalc embedded language. Currently, only trends have been moved-implemented!

The appearance of the diagram is determined by its dimensions hsz*vsz and the source SVG-template tmpl, a number attributes of the root tag of which has special meaning and corresponding to the primitive "Diagram":
- Scale: Markers: font (sclMarkFont), by default "Arial 10".
- Scale: horizontal (sclHor), by default "Markers (2)" and generally provided: "No draw (0)", "Grid (1)", "Markers (2)", "Grid and markers (3)".
- Scale: vertical (sclVer), by default "Grid and markers (3)" and generally provided: "No draw (0)", "Grid (1)", "Markers (2)", "Grid and markers (3)", "Grid (log) (5)", "Markers (log) (6)", "Grid and markers (log) (7)".
- Scale: color (sclColor), by default "gray".
- Scale: Markers: color (sclMarkColor), by default "gray".

Currently, only value archives can be used as a data source, either directly to them or through the DAQ-parameter attribute with the archive. The number of data sources is not directly limited and is written in separate lines of the argument srcs in the format "{addr}:{min}:{max}:{color}[:{scale}[:{width}]]", where:
- addr — address to the value archive or attributes of the DAQ-parameter, for example: "/Archive/va_CPULoad_load", "/DAQ/LogicLev/gen/F3/var";
- min, max — minimum and maximum of the scale, in the scale absence (min >= max), it will be calculated from the real data;
- color — colour of the trend curve;
- scale — separate definition of the trend scale, by default "Global (0)" and generally provided: "Global (0)", "Markers (2)", "Grid and markers (3)", "Markers (log) (6)", "Grid and markers (log) (7)".
- width — width of the trend curve, by default 2.

Author: Roman Savochenko <roman@oscada.org>
Sponsored by: Magomed, SAVTECH
Version: 1.4.0
License: GPLv2