The dialog below is used to add a shading to the selected function. To insert a new shading, you use → . To change an existing shading, you first select it in the funktionslista and use → . The shading is used to mark an area between the function graph and something else.
In the Skuggning tab you can choose between the following types of shadings:
- Mellan funktion och x-axel
This is the most commonly used type of shading. This will shade the area between the graph of the function and the x-axis in the selected interval. If you check Minska till skärningspunkt or Öka till skärningspunkt, the interval will decrease or increase until the graph is crossing the x-axis.
- Mellan funktion och y-axel
This will shade the area between the graph of the function and the y-axis in the selected interval. This is rarely used and probably most useful for parametric functions. Notice that you still use the x-coordinates for the interval. If you check Minska till skärningspunkt or Öka till skärningspunkt, the interval will decrease or increase until the graph is crossing the y-axis.
- Under funktion
This will shade the area below the graph of the function down to the bottom of the graphing area in the selected interval. If you check Minska till skärningspunkt or Öka till skärningspunkt, the interval will decrease or increase until the graph is crossing the bottom of the graphing area.
- Ovanför funktionen
This will shade the area above the graph of the function up to the top of the graphing area in the selected interval. If you check Minska till skärningspunkt or Öka till skärningspunkt, the interval will decrease or increase until the graph is crossing the top of the graphing area.
- Inom funktion
This will shade the area inside the graph of the function in the selected interval. If you check Minska till skärningspunkt or Öka till skärningspunkt, the interval will decrease or increase until the graph is crossing itself. This is especially useful to shade a closed part of a parametric or polar function, but it can also be used to shade standard functions.
- Mellan funktionerna
This will shade the area between the graphs of two functions. The first function is the one you selected in the funktionslista in the main window, before you invoked the dialog. The second function is selected in the list box in the Andra funktionen tab. For standard functions, the interval will be the same for the two functions. For parametric functions, you may select different intervals for the two functions. If you don't select an interval for the second function, it will use the same interval as the first function.
At the Tillval tab shown below, you may change the options for the shading.
- Från
Here you may enter a value, for which you want the shading to start. You specify the x-coordinate if you are using a standard function or the t-parameter if you are using a parametric or polar function. If you don't enter a value, the shading will start at negative infinity. If you place a check mark in Minska till skärningspunkt, the start coordinate of the shading will be decreased from the entered value to the coordinate where the graph is crossing the axis, the edge of the graphing area, itself or another graph, depending of the type of shading selected.
- Till
Here you may enter a value, for which you want the shading to stop. You specify the x-coordinate if you are using a standard function or the t-parameter if you are using a parametric or polar function. If you don't enter a value, the shading will continue until positive infinity. If you place a check mark in Öka till skärningspunkt, the end coordinate of the shading will be increased from the entered value to the coordinate where the graph is crossing the axis, the edge of the graphing area, itself or another graph depending of the type of shading selected.
- Stil
Here you may choose between different styles to use for the shading.
- Färg
Here you may choose the color of the shading.
- Markera ram
Check this to draw a line around the border of the shading. Uncheck it to leave the shading without a border, which is useful if you want two shadings to look as one.
When you have chosen Mellan funktionerna in the Skuggning tab, you may select the second function in the Andra funktionen tab. The dialog with the Andra funktionen tab is shown below.
- Skuggningsområde för andra funktionen
This is used to select the interval for the second function, just like you selected the interval for the first function in the Tillval tab. This is only available for parametric functions and not for standard functions. For standard functions the interval for the second function is always the same as the interval for the first function. If you enter neither a start nor an end of interval for a parametric function, the values for the first function will be used for the second function as well.
Shadings are a great way to mark an area, but if you get weird results, check that you selected the right function and the right interval. If you try to shade an interval crossing an asymptote or your shading is associated with a weird parametric function, you might get weird results. But really, what did you expect?