Touches actions and gestures
This is the portrait view with toolbar (top bar with the three buttons) and tab bar (bottom one) enabled :
The tab bar determines which action will be associated to touches events on the graph itself. The first mode, which is the default one, allows one using one touch gestures to translate (dragging) the graph. By using pinch double touch gestures, one is allowed to rescale the graph, independantly on both axis (an horizontal pinch won't rescale vertical axis... see the first example movie to see it in action.)
Note that it is possible in the settings menu to lock aspect ratio, and in that case the scaling ratio will be the same on both axis, whatever the orientation on the pinch...
Second mode, as its name <<Zero>> implies, allows one to search for roots of a function. It will apply to whatever function is currently drawn, amongst f,g and h user defined functions only, just touch wherever you see a root, and most probably the floating point value of the root you guess will be shown. (If it is not, zoom in a bit a try to give the solver a better seed...)
Note that when displaying graphically the first steps of an iterative sequence satisfying the recurrence : u(n+1) = f(u(n)), then the numeric solver will also look for fixed point for f nearby the point you touched.
Third mode does the same as the former, but for looking for local extrema of f,g or h. Note that this mode has no effect on anything other than f,g or h.
Fourth mode, named <<intersection>> works the same way as the two former ones, and will look for intersection between f,g and h representative curves.
Last mode (whose output is shown on the previous screenshot) will allow you to display values calculated for one function (amongst f, f', g and h) : just touch near one representative curve, then move your finger horizontaly
As for the toolbar, you probably guessed that the Menu button will get you back to the main menu, the Reset axis button will rescale both axis to fit the values defined in the Settings menu. The last button, showing a cross, will hide both the toolbar and the tabbar, allowing one to see the graph in fullscreen. Note that in portrait orientation the status bar will always be present, but will be hidden when in landscape orientation :
When the bars are hidden, to get them back, you can do :
- double tap
- initiating any double touch gesture when in any other mode than Drag & zoom