6 Using MapleNet's Image Generation

In this Chapter

• Description of Image Generation
• URL Specification
• Usage
• Examples

6.1 Description of Image Generation

Users can take advantage of MapleNet's image generation capabilities to embed math or plot images in any web page. These images are created dynamically using simple URLs directed to the MapleNet server and returned in either GIF or JPEG format.

The image generation feature of MapleNet has the following capabilities:

• Creates images of Maple's 2-D math
• Creates images of Maple's 2-D and 3-D plots
• Can specify breakwidth for math output
• Can specify width and height for plots
• Can specify font attributes for math output including font family, size, and color

6.2 URL Specification

The general form of the URL to generate an image is

http://yourserver:port/maplenet/imaging/image?maple=M&type=T&format=FM&width=W&height=H&fontname=FN&fontsize=FS&fontcolor=FC

where

• yourserver and port are the specifications for the server.
• M represents a Maple Expression. This is a required parameter. At the moment this can only be a single Maple expression. See the notes about special characters and URL encoding below.
  e.g., maple=Int(x,x=a..b)=int(x,x=a..b)
• T represents the math type. It can be one of:
  math - the expression M will be output as an image of 2-D Math
  plot - the expression M must be a valid plot command generating either a 2-D or 3-D plot
  auto - (default) the system will attempt to see if the expression contains a plot command; otherwise, it will generate math
  e.g., type=math
• FM represents one of the output formats and can be one of GIF (default) or JPEG.
  e.g., format=jpeg
• W represents the width parameter. For type math, it represents the maximum or break width. If the expression generates an image larger that this the output math will be line wrapped at this pixel width. For expressions that generate a smaller image, the actual width of the output image may be less than W. For type plot, it represents the actual width of the image of the plot. The default value is 300.
  e.g., width=250
• H represents the height parameter. For type math, it is not used. The output image height is dependent on the fontsize and the line wrapping. For type plot, it is the actual height of the output plot. The default value is 300.
  e.g., height=250
• FN represents the font name. This parameter is only relevant for math output. Examples could be Courier, Arial, etc. It is up to the operating system of the server to map the font name to an actual font. The default is Courier.
  e.g., fontname=Arial
• FS represents the fontsize in point size. This parameter is only relevant for math output.
  e.g., fontsize=24
• FC represents the font color. Only relevant for math output. Note that the parameter name in the URL can also be specified as fontcolour instead of fontcolor. The value can either be a name, such as red, or it can be in numeric format. The numeric format is a six-digit number of the form
  rrggbb
  or
  #rrggbb
  where rr, gg, and bb are hex values in the range 00 to FF. The following are examples of some colors:
  
  

  Hex value		Color	Hex value		Color
  #000000		black	#C0C0C0		silver
  #808080		gray	#FFFFFF		white
  #800000		maroon	#FF0000		red
  #800080		purple	#FF00FF		magenta
  #008000		green	#00FF00		lime
  #808000		olive	#FFFF00		yellow
  #000080		navy	#0000FF		blue
  #008080		teal	#00FFFF		cyan

  
  e.g., fontcolor=cyan
  fontcolour=007CF5

URL Line Length Limits

The maximum length of the URL is both browser dependent and server dependent.

URL Encoding

URLs by definition have special meaning for certain characters. This is defined in Internet standards. URL encoding replaces certain ASCII characters with "%" followed by two hexadecimal digits. Hex values correspond to values in the ISO-8859-1 characters. If these characters are required in the Maple Expression, they usually should be included in an encoded format. For example,

a+b

should be written as

a%2Bb

The following list shows the special characters and their encoded form:

Name	Char.	Encoding	Notes (if character is not encoded)
Space		%20
Pound sign	#	%23	will be used as anchor reference
Percent sign	%	%25	percent is encoding character
Ampersand	&	%26	is delimiter for parameters
Plus	+	%2B	will be converted to space
Less than	<	%3C
Equal sign	=	%3D	may be confusing in parameter=value sequence
Greater than	>	%3E
Question mark	?	%3F	is delimiter for start of parameters

So, a math expression of the form

/maplenet/imaging/image?maple=int(sin(x)+cos(x),x=a..b)&font=Courier

becomes

/maplenet/imaging/image?maple=int(sin(x)%2Bcos(x),x%3Da..b)&font=Courier

6.3 Usage

To include a generated image in a web page, use an image generation URL in the 'href' parameter of any <img> tag.

Note: Images are generated dynamically at the time the href URL is sent back to the server. The image is not stored on the server.

6.4 Examples

Copy and paste the following examples into your browser. Be sure to replace localhost:8080 with the specifications for your server.

Math Examples

Show the equation: x-sin(x)

http://localhost:8080/maplenet/imaging/image?maple=x-sin(x)&fontname=Courier&fontsize=18&fontcolor=8D38C9

Show the equation: distance = (1/2)*a(t)*t^2 + v(t)*t + d0

http://localhost:8080/maplenet/imaging/image?maple=distance%3DInt((1/2)*a(t)*t^2%2Bv(t)*t%2Bd0,t%3D0..tMax)&fontname=Courier&fontsize=18&fontcolor=8D38C9

Plot Examples

Show plot of sin(x) from 0 to 2*Pi

http://localhost:8080/maplenet/imaging/image?maple=plot(sin(x),x=0..2*Pi)&width=400&height=200

Show a 3-D plot of x^2 + y^2

http://localhost:8080/maplenet/imaging/image?maple=plot3d(x^2%2By^2,x=-1..1,y=-1..1)&width=400&height=400