Normally when GFE starts up, it displays a default chart. You can alter what is initially displayed by attaching parameters to the URL of the web page. You can override some or all the controls to display whatever initial chart you would like. This will also be the chart GFE will return to when the user clicks on 'reset'.
For example, you can set up chart with all the functions and ranges as you want them, so in a lecture the chart will come up that way immediately. You can set up an unlimited number of different charts this way.
Normally the URL of the GFE looks like this:
To customize the chart, attach parameters to the end of the URL: *
You can create a link in a web page that will take the user to GFE. By adding parameters to the href, you can control how the GFE looks when it is initially displayed. For example:
In Microsoft Word, you insert a link to a web page in the document using the "insert link" menu command. When you do this you will have the opportunity to specify the link text and the address to go to when the user clicks on the link. Simply provide the address with the extra optional parameters to customize how GFE will look when it first comes up. For example:
This is a list of the parameters you can add to the URL. Any you do not provide will take on the default values shown.
Each parameter is available in both long form and short form (shown in parentheses). Use either one. The short form is useful for complex charts that can result in a URL too long for some programs. (For example, in Microsoft Word a hyperlink URL must be less than 256 characters.) The "save as link" command outputs the URL using the short forms.
When a parameter is true/false, the following rules apply: If the value is "true" or "t" it is interpreted as true. All other values are interpreted as false. Not case-sensitive.
|fx||The expression that is used for the first function f(x)||sin(a*x)||fx=sin(6*x)|
|gx||The expression that is used for the second function g(x)||empty||gx=tan(x)|
|hx||The expression that is used for the third function h(x)||empty||gx=a*sin(x)|
|relopf (rf)||Relational operator for f(x) (see note below)||0||relopf=2|
|relopg (rg)||Relational operator for g(x) (see note below)||0||relopg=1|
|reloph (rh)||Relational operator for h(x) (see note below)||0||reloph=3|
|showf (sf)||If true, show the graph for f(x), hidden for any other value||true||showf=false|
|showg (sg)||If true, show the graph for f(g), hidden for any other value||true||showg=t|
|showh (sh)||If true, show the graph for f(h), hidden for any other value||true||sh=false|
|xmax (xh)||The high end of the range of values on the x-axis||4||xmax=8|
|xmin (xl)||The low end of the range of values on the x-axis||-4||xmin=-8|
|ymax (yh)||The high end of the range of values on the y-axis||-3||ymax=7|
|ymin (yl)||The low end of the range of values on the y-axis||-3||ymin=-6|
|amax (ah)||The value at the top end of the slider for variable A||4||amax=10|
|amin (al)||The value at the bottom end of the slider for variable A||0||amin=–3|
|aval (a)||Initial value for the slider for variable A||2||a=7.5|
|As above but for slider B||4
|As above but for slider C||4
|As above but for slider D||4
|thick (th)||If true the graph lines are bold (thick)||false||thick=true|
|mono (ms)||If true, inequlaities are shaded in a uniform gray color||false||mono=true|
|snap (sn)||If true, the sliders will only stop at whole numbers||false||sn=t|
|grid (gr)||If true, the grid and axis labels will be displayed||true||gr=f|
|cursor (cr)||If true the cursor is initially on||false||cr=t|
|cursorx (cx)||The initial value for the cursor x||1||cursorx=1.2|
|2||<=||Less than or equals|
|4||>=||Greater than or equals|
HTML experts will recognize this as the same format as the GET method of posting requests from HTML forms. You could in fact invoke GFE from an HTML form.