|AHELP for CIAO 4.5 ChIPS v1||
Creates a curve (a set of two-dimensional points optionally marked by points or connected by lines)
add_curve([ChipsId,] filename [, transform [, attributes]]) add_curve([ChipsId,] TABLECrate [, transform [, attributes]]) add_curve([ChipsId,] x, y [, transform [, attributes]]) add_curve([ChipsId,] x, y, error_list|None [, transform [, attributes]]) add_curve([ChipsId,] x, y, error_list|None, limits_list|None [, transform [, attributes]])
- 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 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.
- transform - a Crates transform object used to convert the input (x,y) values into the display values.
- attributes - optional parameters which allow the user to configure properties though a structure, list, dictionary 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.
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 "None" may be used.
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.
Please see the section "Curve Preferences and Attributes" below the examples for a list of the curve preferences.
chips> add_curve("lc.fits[cols time, count_rate]")
Plot the time versus count_rate columns from the FITS file "lc.fits". The Data Model virtual filter syntax "[cols time, count_rate]" is used to select the X and Y columns from the file.
chips> add_curve("lc.fits[cols time, count_rate]", ["line.color","red"])
Plot the time versus count_rate columns from the FITS file "lc.fits", and draw the lines between the points in red.
chips> add_curve("lc.fits[cols time, count_rate, stat_err]")
Plot the time versus count_rate columns, and use the stat_err column as symmetric Y errors.
chips> add_curve("lc.fits[cols time, count_rate, stat_err]",["line.color", "red", "err.color", "coral", "symbol.style", "circle", "symbol.size", 6])
Repeat the previous example, this time overriding several of the preference settings for curves.
chips> dat = read_file("lc.fits[cols time, rate, error]") chips> add_curve(dat)
Read in the time, rate, and error columns from a file using the Crates routine read_file, then plot the data.
chips> x = np.arange(11) chips> add_curve(x, x*x)
Plot the curve y = x^2 for the integer values 0 to 10.
chips> z = np.arange(10) chips> add_curve(z, z-4, [z*0.2, z*0.1])
Create a curve with assymetric Y error bars.
chips> x = np.arange(0,10,0.1) chips> set_preference("curve.symbol.style", "none") chips> add_curve(x, np.sin(x), ["line.color", "plum"]) chips> add_curve(x, np.cos(x), ["line.color", 0xf04539, "line.style", "dot"])
Set the symbol.style preference to "none" before adding the curves. Overplot the cosine curve on top of the sine curve, specifying attributes in a list.
chips> cr = read_file("data.fits") chips> x = get_colvals(cr, "X") chips> y = get_colvals(cr, "Y") chips> add_curve(x, y) chips> vals = ChipsCurve() chips> vals.line.style = "none" chips> vals.symbol.fill = False chips> vals.symbol.size = 5 chips> vals.symbol.color = "sienna" chips> set_curve(vals)
Create a curve of the X and Y columns from data.fits. Populate the "vals" structure, then set the curve attributes.
chips> add_image("img.fits") chips> cr = read_file("fov1.fits[ccd_id=3]") chips> x = copy_colvals(cr, "x") chips> y = copy_colvals(cr, "y") chips> tr = get_transform(cr, "EQPOS") chips> add_curve(x, y, tr, ["symbol.style", "none"])
Here we overplot the polygon from a Chandra Field-Of-View file (fov1.fits), representing the edges of ACIS-I3, onto an image. We here take advantage of the transform support and read in the SKY column for the polygon (namely X and Y) and the transform data needed to convert this into the (Ra,Dec) system used to display the image (although we could have used the support for virtual columns to read in the RA and Dec columns directly from the FOV file).
The attributes associated with curves are given in the following table, where the "Set?" column refers to whether the attribute can be changed using the set_curve() command. To change the curve preference settings prepend "curve." to the attribute name.
|baddata||How to handle NaNs and +/-infs in data||omit, ignore: omit means to discard bad data point and leave gap, ignore means discard bad points, connecting the surrounding points||omit||Yes|
|depth||Depth of the curve||see the Depth section of "ahelp chipsopt"||default||Yes|
|err.caplength||Length of the cap drawn on error bars (when err.style is cap).||1 to 100, inclusive.||10||Yes|
|err.color||Color of the curve err bars||name or hex; see the Color section of "ahelp chipsopt"||default||Yes|
|err.down||Plot y down errors if data provided||see the Booleans section of "ahelp chipsopt"||true||Yes|
|err.left||Plot x down errors if data provided||see the Booleans section of "ahelp chipsopt"||true||Yes|
|err.right||Plot x up errors if data provided||see the Booleans section of "ahelp chipsopt"||true||Yes|
|err.style||Specifies the error bar style||bar|line|cap (bar and line are identical)||line||Yes|
|err.thickness||Specifies the thickness of error bars||0.5 to 10.0; see the Thickness section of "ahelp chipsopt"||1||Yes|
|err.up||Plot y up errors if data provided||see the Booleans section of "ahelp chipsopt"||true||Yes|
|limitlength||Length of the bars for upper and lower limits||0 to 1 in plot normalized coordinates||0.05||Yes|
|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 chipsopt"||true||Yes|
|line.color||Color of the curve line||name or hex; see the Color section of "ahelp chipsopt"||default||Yes|
|line.style||the pattern used for the curve line style||see the Line Style section of "ahelp chipsopt"||solid||Yes|
|line.thickness||Thickness of the curve line||0.5 to 10.0; see the Thickness section of "ahelp chipsopt"||1||Yes|
|stem||Stem used for curve id||An alpha-numeric character sequence that does not contain a space||crv||No|
|symbol.angle||The angle, in degrees, of rotation for the curve symbols||-360.0 to 360.0||0.0||Yes|
|symbol.color||Color of the curve symbols||name or hex; see the Color section of "ahelp chipsopt"||default||Yes|
|symbol.fill||Should the curve symbols be filled or not||see the Booleans section of "ahelp chipsopt"||true||Yes|
|symbol.size||Size of the curve symbols||1 to 100||2||Yes|
|symbol.style||The shape of the glyph used as the curve symbols||see the Symbol Styles section of "ahelp chipsopt"||cross||Yes|
It is now possible to create a curve for a single-element array, such as
chips> add_curve([100.23], [-1234.87])
In CIAO 4.4 the call would succeed but the point would not be displayed.
Support has been improved for curves containing "small" y values (such as values smaller than 1e-14).
See the bugs pages on the ChIPS website for an up-to-date listing of known bugs.