divgraph.js Functions

This document describes the divgraph.js functions.
See info.htm for user parameter information.

The divgraph.js functions fall into four basic categories:

Primary Interface Functions (click to go to a description)
GRadddata(sdata,Data,Labels,Info) GRaddfunction(f_of_x,Info) GRaddpoint(x,y,label,c,xytype,ngraph) GRaddpointref(x,y,label,c,ref,xytype,ngraph) GRaddtext(x,y,stext,c,xytype,ngraph) GRclosegraphdocument(ngraph) GRclosegraphwindow(ngraph,delay) GRdrawgraph(f_of_x,Data,Labels,Info,doc) GRinit() GRopengraphframe(frame) GRopengraphwindow(w,h,t,l) GRreplot(ngraph,xoff,yoff,doc2,w,h,t,l) GRsetgraphwindow(w)
Secondary Interface Functions (click to go to a description)
GRalert(a,b,c,d,...) GRdebugwrite(a,b,c,d,...) GRdiv(i,doc) GRdivinfo(i,doc) GRdivmove(i,x,y,xytype,ngraph) GRdivshow(i,TF,ngraph) GRdivwrite(i,s,x,y,xytype,ngraph) GRfixpower(s,format) GRgetleastsquares(Data,L) GRgetoffset(s) GRgraph(x,y) GRgetnewwindow(s,opt) GRinitdivs() GRmouseevent(e,x,y,scmd) GRprompt(q,a) GRrect(x1,y1,y2,y2,c,xytype,ngraph) GRresize() GRroundoff(x,ndec) GRsetgraph(ngraph,tolist) GRshow(obj,objName,signore,sonly) GRxof(x) GRyof(y)
Internal divgraph.js Functions (click to view)
GRcleargraph(setdefaults) GRcopy(Afrom,Ato,list...) GRdatacolor(D) GRdotics(tic0,tmin,tmax,minort,majort,stylex,styley,plotx,ploty, force,isy,doticnums,numx,numy,ndig,nignore) GRfindparen(s,ipt0,idirect) GRgetdata(sdata,Data,Labels) GRgetinfo(A,skey,def) GRgraphpoint(i,scolor,slabel) GRinrange(x,a,b) GRlabelof(i,s,c,a,w) GRLSQ(L,x,y) GRLSR(L,x,y) GRndig(n) GRnewdata(A,x,P) GRnewdiv(P) GRnewlabel(s,x,y,c) GRnewpt(i,x,y,Data,Labels,width,height,c) GRnewstyle(left,top,width,height,color,label) GRptof(i,w,h,c,a) GRsort(a,b) GRspline(Data,i) GR10(x)
User Math Functions (click for a discussion)
function cos(x){return Math.cos(x)} function ln(x){return Math.log(x)} function log(x){return Math.LOG10E*Math.log(x)} function sin(x){return Math.sin(x)} function sqr(x){return Math.pow(x,0.5)} function sqrt(x){return Math.pow(x,0.5)} function tan(x){return Math.sin(x)/Math.cos(x)}

parameter	default	description
Primary Interface Functions
These ten functions comprise the main programming interface. For detailed examples of their use, see examples.htm.
view function `GRadddata(sdata,Data,Labels,Info)` adds x,y data to a previous graph initiated with `GRdrawgraph()` NOTE: CANNOT BE RUN AFTER DOCUMENT IS CLOSED
sdata	PROMPT	x,y data in pairs, one pair per line, or a continuous stream of x,y,x,y... data. If Data.length=0, then the user is prompted.
Data[ ]	new Array()	x,y data in the form [x,y,color,label], where color.gif is a valid GIF file name, and label is a label for the point. Used only if sdata is an empty string. Color and label are optional. If no verical bar is present in the label, the label is an alt label, which is only seen when the user moves the mouse over the point. If a vertical bar ("\|") is present in the label, then text to the left of this bar becomes the alt label, while text after the bar becomes the displayed label.
Labels[ ]	new Array()	labels for x,y data. If Labels.length>0, then any labels in Data[ ] are ignored.
Info[ ]	new Array()	information array -- see info.htm
actions:		This function allows entry of a second set of data BEFORE the graphing document is closed. After that, `GRaddpoint()` must be used instead.
return:		plot number, the index into GR.List[ ] for this plot. In addition, if sdata is nonblank, then Data[ ] is filled with x,y pairs.
view function `GRaddfunction(f_of_x,Info)` adds a function of x to a previous graph initiated with `GRdrawgraph()` NOTE: CANNOT BE RUN AFTER DOCUMENT IS CLOSED
parameter	default	description
f_of_x	PROMPT	function of x (a string)
Info[ ]	new Array()	information array -- see info.htm
actions:		This function allows entry of a second function of x BEFORE the graphing document is closed.
return:		plot number, the index into GR.List[ ] for this plot.
view function `GRaddpoint(x,y,label,c,xytype,ngraph)` Allows the addition of a point at the specified x,y locations. NN4: CANNOT BE RUN BEFORE DOCUMENT IS CLOSED
parameter	default	description
x	PROMPT	x-coordinate
y	PROMPT	y-coordinate
label	PROMPT	text to associate with this point. If no verical bar is present in the label, the label is an alt label, which is only seen when the user moves the mouse over the point. If a vertical bar ("\|") is present in the label, then text to the left of this bar becomes the alt label, while text after the bar becomes the displayed label.
c	GR.colorlast	c.gif must be a valid GIF file.
xytype	GRUSER	GRUSER indicates coordinates are user-based GRDOC indicates coordinates are document-based, with 0,0 at the top left corner of the plotting surface (as specified by Info.graphleft and Info.graphtop, not the window) with y running DOWN from the top. GRANCHOR indicates coordinates based on a graph anchor element such as an image or "a" tag (indicated by setting `Info.anchor` to the name of the element).
ngraph	GR.thisgraph	the graph number associated with this point, starting with 1
return:
actions:		only the total number of additional points, as specified by Info.maxaddpoints in a previous call to `GRdrawgraph()` are allowed. If this number is exceeded, then the request is ignored.
return:		div number associated with this point, or 0 if the maximum number of points has been exceeded. This number can be used later in `GRdivwrite()` or `GRdivmove()`.
view function `GRaddpointref(x,y,label,c,ref,xytype,ngraph)` Allows the addition of a web link at the specified x,y locations. NN4: CANNOT BE RUN BEFORE DOCUMENT IS CLOSED
parameter	default	description
x	REQUIRED	x-coordinate
y	REQUIRED	y-coordinate
label	REQUIRED	text to associate with this point. If no verical bar is present in the label, the label is an alt label, which is only seen when the user moves the mouse over the point. If a vertical bar ("\|") is present in the label, then text to the left of this bar becomes the alt label, while text after the bar becomes the displayed label.
c	REQUIRED	c.gif must be a valid GIF file.
ref	REQUIRED	the reference; "..." in <a href="....">
xytype	GRUSER	GRUSER indicates coordinates are user-based GRDOC indicates coordinates are document-based, with 0,0 at the top left corner of the plotting surface (as specified by Info.graphleft and Info.graphtop, not the window) with y running DOWN from the top. GRANCHOR indicates coordinates based on a graph anchor element such as an image or "a" tag (indicated by setting `Info.anchor` to the name of the element).
ngraph	GR.thisgraph	the graph number associated with this point, starting with 1
return:
actions:		only the total number of additional points, as specified by Info.maxaddpoints in a previous call to `GRdrawgraph()` are allowed. If this number is exceeded, then the request is ignored.
return:		div number associated with this point, or 0 if the maximum number of points has been exceeded. This number can be used later in `GRdivwrite()` or `GRdivmove()`. }
view function `GRaddtext(x,y,stext,c,xytype,ngraph)` Allows the addition of text at the specified x,y locations. NN4: CANNOT BE RUN BEFORE DOCUMENT IS CLOSED
parameter	default	description
x	PROMPT	x-coordinate
y	PROMPT	y-coordinate
stext	PROMPT	text to display
c	GR.colorlast	JavaScipt color to use. This parameter may include additional information to be included in the font tag (when no alignment is specified) or in the td tag (when alignment is specified, for example, with `red align=center`. The color must come first, and the width of the tag, if aligned, must not exceed 200 pixels.
xytype	GRUSER	GRUSER indicates coordinates are user-based GRDOC indicates coordinates are document-based, with 0,0 at the top left corner of the plotting surface (as specified by Info.graphleft and Info.graphtop, not the window) with y running DOWN from the top. GRANCHOR indicates coordinates based on a graph anchor element such as an image or "a" tag (indicated by setting `Info.anchor` to
ngraph	GR.thisgraph	the graph number associated with this point, starting with 1
actions:		only the total number of additional points, as specified by Info.maxaddpoints in a previous call to `GRdrawgraph()` are allowed. If this number is exceeded, then the request is ignored.
return:		div number associated with this point, or 0 if the maximum number of points has been exceeded. This number can be used later in `GRdivwrite()` or `GRdivmove()`.
view function `GRclosegraphdocument(doc)` Closes the document at the end of graphing. This should be standard procedure.
parameter	default	description
doc	GR.doc	the document to close
actions:		closes the specified document.
return:		closed document
view function `GRclosegraphwindow(ngraph,delay)` Closes one or more graph windows. (Graphs in the main document are not affected.)
parameter	default	description
ngraph	0	the number of the graph for which the window is to be closed. Zero indicates all open graph windows.
delay	20	The delay for a `setTimeout()` in milliseconds.
actions:		closes the specified graph window(s)
return:		null
view function `GRdrawgraph(f_of_x,Data,Labels,Info,doc)` The primary interface for graphing after execution of `GRopengraphwindow()` , `GRopengraphframe()`, or `GRsetgraphwindow()`
parameter	default	description
f_of_x	""	f(x) or x,y paired data, either "x,y,x,y,x,y..." or one x,y pair per line.
Data[ ]	new Array()	x,y data in the form [x,y,color,label], where color.gif is a valid GIF file name, and label is text to include with the point. If no verical bar is present in the label, the label is an alt label, which is only seen when the user moves the mouse over the point. If a vertical bar ("\|") is present in the label, then text to the left of this bar becomes the alt label, while text after the bar becomes the displayed label. Color and label are optional.
Labels[ ]	new Array()	labels for x,y data. If Labels.length>0, then any labels in Data[ ] are ignored.
Info[ ]	new Array()	information array -- see info.htm
doc	GR.doc	graphing document
actions:		Several default actions are available. If no parameters are given, the user is prompted both for the f(x) or x,y data and for the range of x when f(x) is given. If only the first parameter is given, and it is found to be a function of x, then the user is prompted for the range of x. If f_of_x is an empty string, Data[ ] is used. If Labels.length>0, then Data labels are ignored.
return:		plot number, the index into GR.List[ ] for this plot. In addition, if f_of_x is used, then Data[ ] is filled with x,y pairs.
view function `GRinit()` initializes the divgraph.js package
actions:		resets all arrays and variables to their default values. Reuses all variables and structures. Recommended to be called whenever previous graphs are not being saved or displayed.
return:		null
view function `GRopengraphframe(frame)` Open a new graph document in the specified frame
parameter	default	description
frame	REQUIRED	frame for which the document is to be opened
actions:		GR.win is set the new frame, and GR.doc is set to the frame document, which is opened. This initiates an overwriting of any document currently that frame.
return:		frame.document
view function `GRopengraphwindow(w,h,t,l)` Opens a new window and its associated document for a new graph.
parameter	default	description
w	300	window width
h	300	window height
t	50	window top
l	50	window left
actions:		Creates a new window with options based on the GR.winoptions template. Sets GR.win and GR.doc.
return:		new graph window
view function `GRreplot(ngraph,xoff,yoff,doc2,w,h,t,l)` replotting of data for printing with Netscape Navigator or for redisplaying the data in a new window
parameter	default	description
ngraph	GR.thisgraph	plot number (index into `GR.List[ ]`, returned by `GRdrawgraph()`
xoff	0	x-offset from original
yoff	0	y-offset from original
doc2	new	graph document
w	most recent	window width
h	most recent	window height
t	most recent	window top
l	most recent	window left
actions:		if doc2 is not specified, the new graph document is closed, and the old window is closed. GR.win and GR.doc point to the new graph.
return:		new graph window if creation was necessary, or null if it was not.
view function `GRsetgraphwindow(w)` Sets the window and its currently open document to be the current graphing window and document. Assumes an open document already.
parameter	default	description
w	window	window or frame to be used (defaults to main window)
actions:		GR.win is set the specified window, and GR.doc is set to the window's document. However, no document is opened. This allows writing into the main document or into a frame that has an already-opened document currently being written to. Use this function instead of `GRopengraphwindow()` or `GRopengraphframe()` to open a graph in a document that is currently being written.
return:		w.document
Math Interface Functions
These seven functions allow the user to specify common-use math functions instead of JavaScript math. They are the only functions in the package that do not begin with "GR" and probably are only of use if the user is expected to specify the math function to be plotted. They are not called by any GR functions and may be overwritten, complemented, or discarded.
function sin(x){return Math.sin(x)} function cos(x){return Math.cos(x)} function tan(x){return Math.sin(x)/Math.cos(x)} function log(x){return Math.LOG10E*Math.log(x)} function ln(x){return Math.log(x)} function sqrt(x){return Math.pow(x,0.5)} function sqr(x){return Math.pow(x,0.5)}
Secondary Interface Functions
These 13 functions might be of general use, but are primarily used from within the divgraph.js package.
view function `GRalert(a,b,c,d,...)` shows an alert in the graphing document
parameter	default	description
any	REQUIRED	any number of parameters may be displayed. Each separate parameter is displayed on a separate line of the message box.
actions:		This also serves to bring a graph window to the foreground when necessary. Standard alerts will bring the calling page to the foreground, probably hiding the graph.
return:		null
view function `GRdebugwrite(a,b,c,d,...)` shows a message in a new window
parameter	default	description
any	REQUIRED	any number of parameters may be displayed. Each separate parameter is displayed on a separate line of the new window.
actions:		opens a new window displaying the specified string.
return:		null
view function `GRdiv(i,doc)`
parameter	default	description
i	REQUIRED	refering to div "G"+i
doc	REQUIRED	any document with divs of this form
actions:		this is a browser-blind call to get a div handle.
return:		(GR.isnn4?doc.layers["G"+i]:eval("doc.all.G"+i))
view function `GRdivinfo(i,doc)` this function allows a determination of the contents of div "#G"+i in document doc
parameter	default	description
i	REQUIRED	refering to div "G"+i
doc	REQUIRED	graphing document
actions:		this is a browser-blind call to get a div HTML contents. Since NN4 does not proved the `innerHTML` property, this is provided by an array GR.innerHTML, which is set up as divs are written.
return:D, an array with elements D.innerHTML, D.offsetLeft, and D.offsetTop
view function `GRdivmove(i,x,y,xytype,ngraph)` move the specided div "G"+i to the specified location
parameter	default	description
i	REQUIRED	refering to div "G"+i
x	REQUIRED	x-coordinate
y	REQUIRED	y-coordinate
xytype	GRUSER	GRUSER indicates coordinates are user-based GRDOC indicates coordinates are document-based, with 0,0 at the top left corner of the plotting surface (as specified by Info.graphleft and Info.graphtop, not the window) with y running DOWN from the top. GRANCHOR indicates coordinates based on a graph anchor element such as an image or "a" tag (indicated by setting `Info.anchor` to
ngraph	GR.thisgraph	the graph number associated with this point, starting with 1
actions:		repositions the div; automatically shows it if hidden
return:		null
view function `GRdivshow(i,TF,ngraph)` shows or hides the specified div
parameter	default	description
i	REQUIRED	refering to div "G"+i
TF	true	whether to show the div; true or false
ngraph	GR.thisgraph	the graph number associated with this point, starting with 1
actions:		shows/hides the div;
return:		null
view function `GRdivwrite(i,s,x,y,xytype,ngraph)` writes HTML to a specified div of id "G"+i, moving it, if that too is specified
parameter	default	description
i	REQUIRED	refering to div "G"+i
s	REQUIRED	HTML to write
x	OPTIONAL	x-coordinate
y	OPTIONAL	y-coordinate
xytype	GRNONE	GRUSER indicates coordinates are user-based GRDOC indicates coordinates are document-based, with 0,0 at the top left corner of the plotting surface (as specified by Info.graphleft and Info.graphtop, not the window) with y running DOWN from the top. GRANCHOR indicates coordinates based on a graph anchor element such as an image or "a" tag (indicated by setting `Info.anchor` to GRNONE or no parameter present indicates write only, without a move.
ngraph	GR.thisgraph	the graph number associated with this point, starting with 1
actions:		write to and optionally repositions the div; automatically shows the div if hidden
return:		null
view function `GRfixpower(s,format)` convert standard user form a^b to Math.pow(a,b)
parameter	default	description
s	REQUIRED	the string to search for a^b in
format	"Math.pow(%1,%2)"	the format
actions:		All occurances of a^b are replaced in a format, where a is %1 and b is %2. Preceding and subsequent string information is recognized and left unchanged. Parentheses are recognized. For example, 3(5+3)^7+1 becomes 3Math.pow((5+3),7)+1.
return:		format replaced as specified
view function `GRgetleastsquares(Data,L)` calculates a least squares fit on x,y pairs in Data
parameter	default	description
Data[ ]	REQUIRED	data in the form of x,y pairs
L[ ]	REQUIRED	return array
actions:		calculates least squares fit
return:		L.m (slope), L.b (intercept), L.r2 (r²)
view function `GRgetoffset(s)` get the absolute x,y position of a page element.
parameter	default	description
s	REQUIRED	the name of the element, as indicated in a "name=" parameter of an HTML tag.
actions:		The x,y coordinates of the element are determined. This function is used for finding a specified anchor's page position initially and upon page resizing.
return:		an array, where array.left=x and array.top=y
view function `GRgraph(x,y)` find the graph associated with a specific absolute document x,y position.
parameter	default	description
x,y	REQUIRED	document-based x and y coordinates.
actions:		Generally, this function is used to associate a user's mouse clicks with a specific graph.
return:		the graph number of the graph whose plotting surface contains these x,y coordinates.
view function `GRmouseevent(e,x,y,scmd)` responds to user clicks and moves of the mouse
parameter	default	description
e	event	event structure from Netscape Navigator only
x,y	event x and y	x,y coordinates (only for testing)
scmd	null	the function name to which to pass structure information (only for testing)
actions:		responds to mouse events
return:		passes on the event structure (from the browser) along with a structure indicating the button that was pressed (in the case of mousedown and mouseup) as well as the graph number for the graph that was clicked on and the x,y coordinates in document, anchor, and user systems. See examplec.htm for more information.
view function `GRgetnewwindow(s,opt)`
parameter	default	description
s	REQUIRED	URL of page to open, or "" for blank window
opt	REQUIRED	option string indicating size, menu, scrolling, and other options
actions:		A new window with a unique name and its associated document are created
return:		handle to new window
view function `GRinitdivs()`
actions:		checks for browser compatibility; sets GR.isnn4 and GR.isie4
return:		true if successful, false if unsuccessful
view function `GRprompt(q,a)` generates a user prompt in the graph window
parameter	default	description
s	REQUIRED	prompt question string
a	REQUIRED	prompt default answer string
actions:		brings the graph window forward and produces a prompt in it. In contrast, a simple prompt() will generally hide a visible graph window behind the main page.
return:		prompt result string or null (canceled)
view function `GRrect(x1,y1,x2,y2,c,xytype,ngraph) ,y,label,c,xytype,ngraph)` create a string representing a rectangle
parameter	default	description
x1,y1	REQUIRED	upper left coordinates
x2,y2	REQUIRED	lower right coordinates
c	GR.colorlast	c.gif must be a valid GIF file.
xytype	GRUSER	GRUSER indicates coordinates are user-based GRDOC indicates coordinates are document-based, with 0,0 at the top left corner of the plotting surface (as specified by Info.graphleft and Info.graphtop, not the window) with y running DOWN from the top. GRANCHOR indicates coordinates based on a graph anchor element such as an image or "a" tag (indicated by setting `Info.anchor` to the name of the element).
ngraph	GR.thisgraph	the graph number associated with this point, starting with 1
return:
actions:		creates a string corresponding to a box with upper left corner x1,y1 and lower right corner x2,y2.
return:		<img>HTML tag for use in `GRdivwrite()`
view function `GRresize()` moves the graph to the correct anchored position if the web page is resized
actions:		This function is called when the page is resized if an anchor is indicated for a graph. For proper function under Internet Explorer, the <body> tag must contain "onresize=GRresize()" or else a reference to a function that itself calls GRresize().
return:		1
view function `GRroundoff(x,ndec)` rounds off a number to a specified number of digits
parameter	default	description
x	REQUIRED	number to be rounded
ndec	depends	number of digits to round: ndec<0 for floating (scientific notation) ndec>0 for fixed notation absent: do "reasonable" roundoff
actions:		If ndec is omitted, then it is determined by: \|x\|>=9999 -2 \|x\|<0.01 -2 \|x\|>=10 0 \|x\|>=1 1 \|x\|>=0.1 2 \|x\|>=0.01 3
return:		rounded number as a string
view function `GRsetgraph(ngraph,tolist)` set current graph to be ngraph
parameter	default	description
ngraph	REQUIRED	the number of the graph to make the default graph
tolist	false	true:transfers save current graph information to this graph number (not recommended);false:load this graph information (from GR.List[ngraph]) into the current information (in GR)
actions:		this function needs to be called only if you have multiple graphs and are using GRxof() or GRyof() and no other calls have been made, such as to GRdivmove() or GRdivwrite(), to set the graph. Critical elements in GR.List are transferred to GR so that proper positioning can occur. After calling GRsetgraph(), the "ngraph" parameter may be left off in all other functions requiring it.
return:		null
view function `GRshow(obj,objName,signore,sonly)` displays all elements of an object
parameter	default	description
obj	REQUIRED	object to be enumerated
objName	"obj"	name to supply for the object
signore	null	ignore all elements containing this text in their name
sonly	null	include only elements containing this in their name
actions:		enumerates the object for debugging purposes. Use with GRalert() or GRdebugwrite(). For example, GRalert(GRshow(document.anchors,"document.anchors")) or GRdebugwrite(GRshow(document.anchors,"document.anchors"))
return:		string of all of the object's elements and their definitions
view function `GRxof(x)` converts user x-coordinate to document coordinates
parameter	default	description
x	REQUIRED	user x-coordinate
return:		Math.round(GR.left+(x-GR.xmin)*GR.xfactor)
view function `GRyof(y)` converts user y-coordinate to document coordinates
parameter	default	description
y	REQUIRED	user y-coordinate
return:		Math.round(GR.top+GR.height-(y-GR.ymin)*GR.yfactor)

divgraph.js Functions

This document describes the divgraph.js functions. See info.htm for user parameter information.

Primary Interface Functions

Math Interface Functions

Secondary Interface Functions

This document describes the divgraph.js functions.
See info.htm for user parameter information.