add_curve( [ChipsId,] filename [,attributes]);
add_curve( [ChipsId,] TABLECrate [,attributes]);
add_curve( [ChipsId,] x, y [,attributes]);
add_curve( [ChipsId,] x, y, error_list|NULL [,attributes]);
add_curve( [ChipsId,] x, y, error_list|NULL, limits_list|NULL
[,attributes]);

Description

• ChipsId - an optional ChipsId structure containing values to modify the currency state for the command.
• TABLECrate/filename - input data, specified as a filename or a TABLECrate ("ahelp sl.crates crates")
• x - array of x data points
• y - array of y data points
• error_list - optional list of up to four error arrays. One array = symmetrical y errors. Two arrays = ydown and yup errors. Three arrays = ydown, yup, and xdown errors. Four arrays = ydown, yup, xdown, and xup errors.
• limits_list - optional list of upper and/or lower limits. The list may be empty, y limits, or y and x limits.
• attributes - optional parameters which allow the user to configure properties though a structure, list, or attribute string.

The add_curve command creates a curve whose attributes are specified by user preferences or in an attribute list. The new curve becomes current by default; providing a ChipsId overrides the currency state. A curve needs a minimum of a pair of numeric data arrays of the same length to plot.

If an existing plot is current, the curve is added to that plot. If there is no current plot, one is created and the curve is placed in it. To overplot curves, simply add them all to the same plot object.

Up to six additional data columns may be provided as error and limits information. The error and limits information is interpreted based on how many columns are supplied to the command, as described above. On account of this, an entry for the error_list array must be provided in order to include limits data. If no error_list is needed, the value "NULL" may be used.

Customizing the Curve

There are several attributes that control the curve characteristics. The attributes can be set to the ChIPS defaults, values provided in the add_curve command, or values from the user's preference file.

The attributes may also be modified with the set_curve command at any time; see "ahelp sl.chips set_curve" and "ahelp sl.chips setget" for more information.

The attributes associated with curves are:

Attribute	Description	Options	Default
baddata	How to handle NaNs and +/-infs in data	omit - discard bad data point and leave gap ignore - discard bad point but connect prev good w/ next	omit
depth	Integer value indicating line depth	see the Depth section of "ahelp sl.chips chipsopt"	100
err.color	Color of the curve err bars	see the Color section of "ahelp sl.chips chipsopt"	default
err.down	Plot y down errors if data provided	true/false	true
err.left	Plot x down errors if data provided	true/false	true
err.right	Plot x up errors if data provided	true/false	true
err.style	Specifies the error bar style	bar|line|cap (bar and line are identical)	line
err.thickness	Specifies the thickness of error bars	0.5:9; see the Thickness).	1
err.up	Plot y up errors if data provided	true/false	true
limitlength	Length of the bars for upper and lower limits	0:1 in plot normalized coordinates	0.05
limitoverride	Should both the limit and the error bar be drawn on a point?	true = hide the errors, false = show the errors; see the Booleans section of "ahelp sl.chips chipsopt"	true
line.color	Color of the curve line	see the Color section of "ahelp sl.chips chipsopt"	default
line.style	the pattern used for the curve line style	see the Line Style section of "ahelp sl.chips chipsopt"	solid
line.thickness	Thickness of the curve line	see the Thickness section of "ahelp sl.chips chipsopt"	1
stem	Stem used for curve id	Alphanumeric	crv
symbol.angle	The angle of rotation for the curve symbols	-360.0:360.0	0.0
symbol.color	Color of the curve symbols	see the Color section of "ahelp sl.chips chipsopt"	default
symbol.fill	Should the curve symbols be filled or not	see the Booleans section of "ahelp sl.chips chipsopt"	true
symbol.size	Size of the curve symbols	1:100	2
symbol.style	The shape of the glyph used as the curve symbols	see the Symbol Style section of "ahelp sl.chips chipsopt"	cross

chips> add_curve("lc.fits[cols time, count_rate]");

chips> add_curve("lc.fits[cols time, count_rate]",{"line.color","red"});

chips> add_curve("lc.fits[cols time, count_rate, stat_err]");

chips> add_curve("lc.fits[cols time, count_rate,
stat_err]",{"line.color", "red", "err.color", "coral", "symbol.style",
"circle", "symbol.size", 6]);

chips> dat = read_file("lc.fits[cols time, rate, error]");
chips> add_curve(dat);

chips> x = [0:10];
chips> add_curve(x, x^2);

chips> z = [0:9];
chips> add_curve(z,z-4,{z*.2,z*.1});

chips> x = [0:10:0.1];
chips> set_preference("curve.symbol.style","none");
chips> add_curve(x,sin(x),{"line.color","plum"});
chips> add_curve(x,cos(x),{"line.color",0xf04539, "line.style", "dot"});

chips> in = read_file("data.fits");
chips> x = get_colvals(in, "X");
chips> y = get_colvals(in, "Y");
chips> add_curve(x, y);
chips> vals = ChipsCurve;
chips> vals.line.style = "none";
chips> vals.symbol.fill = 0;
chips> vals.symbol.size = 5;
chips> vals.symbol.color = "sienna";
chips> set_curve(vals);