slider {aplpack}

slider / button control widgets

Description

slider and gslider construct a Tcl/Tk-widget with sliders and buttons to demonstrate the effects of variation of parameters on calculations and plots.

Usage

slider(sl.functions, sl.names, sl.mins, sl.maxs, sl.deltas, sl.defaults, but.functions,
  but.names, no, set.no.value, obj.name, obj.value, reset.function, title, prompt=FALSE,
  sliders.frame.vertical=TRUE)

gslider(sl.functions, sl.names, sl.mins, sl.maxs, sl.deltas, sl.defaults, but.functions,
  but.names, no, set.no.value, obj.name, obj.value, reset.function, title, prompt=FALSE,
  sliders.frame.vertical=TRUE, hscale=1, vscale=1,
  pos.of.panel = c("bottom","top","left","right")[1])

Arguments

sl.functions

set of functions or function connected to the slider(s)

sl.names

labels of the sliders

sl.mins

minimum values of the sliders' ranges

sl.maxs

maximum values of the sliders' ranges

sl.deltas

change of step per click

sl.defaults

default values for the sliders

but.functions

function or list of functions that are assigned to the button(s)

but.names

labels of the buttons

no

slider(no=i) requests slider i

set.no.value

slider(set.no.value=c(i,val)) sets slider i to value val

obj.name

slider(obj.name=name) requests the value of variable name from environment slider.env

obj.value

slider(obj.name=name,obj.value=value) assigns value to variable name in environment slider.env

reset.function

function that induce a reset.button and contains the commands of it.

title

title of the control window

prompt

if TRUE slider functions are called by moving a slider, if FALSE slider functions are called after releasing the mouse button

sliders.frame.vertical

if TRUE the sliders are stacked one above the other; otherwise they are positioned side by side

hscale

horizontal scale factor for image size; compare tkrplot in package tkrplot

vscale

vertical scale factor for image size; compare tkrplot in package tkrplot

pos.of.panel

position of the panel field for sliders and buttons. Value of pos.of.panel: bottom, top, left or right.

Details

slider constructs a separated panel for controlling the parameters whereas gslider integrates a graphical device and buttons and sliders within one window.

The following actions can be done: a) definition of (multiple) sliders and buttons, b) request or specification of slider values, and c) request or specification of variables in the environment slider.env. The management takes place in the environment slider.env. If slider.env is not found it is generated.

Definition ... of sliders: First of all you have to define sliders, buttons and the attributes of them. Sliders are established by six arguments: sl.functions, sl.names, sl.minima, sl.maxima,sl.deltas, and sl.defaults. The first argument, sl.functions, is either a list of functions or a single function that contains the commands for the sliders. If there are three sliders and slider 2 is moved with the mouse the function stored in sl.functions[[2]] (or in case of one function for all sliders the function sl.functions) is called.

DEFINITION ... of buttons: Buttons are defined by a vector of labels but.names and a list of functions: but.functions. If button i is pressed the function stored in but.functions[[i]] is called.

REQUESTING ... a slider: slider(no=1) returns the actual value of slider 1, slider(no=2) returns the value of slider 2, etc. You are allowed to include expressions of the type slider(no=i) in functions describing the effect of sliders or buttons.

SETTING ... a slider: slider(set.no.value=c(2,333)) sets slider 2 to value 333. slider(set.no.value=c(i,value)) can be included in the functions defining the effects of moving sliders or pushing buttons.

VARIABLES ... of the environment slider.env: Sometimes information has to be trransferred back and forth between functions defining the effects of sliders and buttons. Imagine for example two sliders: one to control p and another one to control q, but they should satisfy: p+q=1. Consequently, you have to correct the value of the first slider after the second one was moved. To prevent the creation of global variables store them in the environment slider.env. Use slider(obj.name="p.save",obj.value=1-slider(no=2)) to assign value 1-slider(no=2) to the variable p.save . slider(obj.name=p.save) returns the value of variable p.save.

Dependencies The function gslider depends on package tkrplot.

Value

Using slider in definition mode slider returns the value of new created the top level widget. slider(no=i) returns the actual value of slider i. slider(obj.name=name) returns the value of variable name in environment slider.env. gslider return in definition mode the result of tkrplot which was called to construct the widget.

Author(s)

Hans Peter Wolf

Examples

# example 1, sliders only
if(interactive()){
## This example cannot be run by examples() but should work in an interactive R session
plot.sample.norm<-function(){
 refresh.code<-function(...){
   mu<-slider(no=1); sd<-slider(no=2); n<-slider(no=3)
   x<-rnorm(n,mu,sd)
   plot(x)
 }
 slider(refresh.code,sl.names=c("value of mu","value of sd","n number of observations"),
       sl.mins=c(-10,.01,5),sl.maxs=c(+10,50,100),sl.deltas=c(.01,.01,1),sl.defaults=c(0,1,20))
}
plot.sample.norm()
}

# example 2, sliders and buttons
if(interactive()){
## This example cannot be run by examples() but should work in an interactive R session
plot.sample.norm.2<-function(){
 refresh.code<-function(...){
   mu<-slider(no=1); sd<-slider(no=2); n<-slider(no=3)
   type=  slider(obj.name="type")
   x<-rnorm(n,mu,sd)
   plot(seq(x),x,ylim=c(-20,20),type=type)
 }
 slider(obj.name="type",obj.value="l")
 slider(refresh.code,sl.names=c("value of mu","value of sd","n number of observations"),
       sl.mins=c(-10,.01,5),sl.maxs=c(10,10,100),sl.deltas=c(.01,.01,1),sl.defaults=c(0,1,20),
       but.functions=list(
              function(...){slider(obj.name="type",obj.value="l");refresh.code()},
              function(...){slider(obj.name="type",obj.value="p");refresh.code()},
              function(...){slider(obj.name="type",obj.value="b");refresh.code()}
       ),
       but.names=c("lines","points","both"))
}
plot.sample.norm.2()
}

# example 2a, sliders and buttons and graphics in one window
if(interactive()){
## This example cannot be run by examples() but should work in an interactive R session
plot.sample.norm.2<-function(){
 refresh.code<-function(...){
   mu<-slider(no=1); sd<-slider(no=2); n<-slider(no=3)
   type=  slider(obj.name="type")
   x<-rnorm(n,mu,sd)
   plot(seq(x),x,ylim=c(-20,20),type=type)
 }
 slider(obj.name="type",obj.value="l")
 gslider(refresh.code,sl.names=c("value of mu","value of sd","n number of observations"),
       sl.mins=c(-10,.01,5),sl.maxs=c(10,10,100),sl.deltas=c(.01,.01,1),sl.defaults=c(0,1,20),
       but.functions=list(
              function(...){slider(obj.name="type",obj.value="l");refresh.code()},
              function(...){slider(obj.name="type",obj.value="p");refresh.code()},
              function(...){slider(obj.name="type",obj.value="b");refresh.code()}
       ),
       but.names=c("lines","points","both"))
}
plot.sample.norm.2()
}

# example 3, dependent sliders
if(interactive()){
## This example cannot be run by examples() but should work in an interactive R session
print.of.p.and.q<-function(){
 refresh.code<-function(...){
   p.old<-slider(obj.name="p.old")
   p<-slider(no=1); if(abs(p-p.old)>0.001) {slider(set.no.value=c(2,1-p))}
   q<-slider(no=2); if(abs(q-(1-p))>0.001) {slider(set.no.value=c(1,1-q))}
   slider(obj.name="p.old",obj.value=p)
   cat("p=",p,"q=",1-p,"\n")
 }
 slider(refresh.code,sl.names=c("value of p","value of q"),
       sl.mins=c(0,0),sl.maxs=c(1,1),sl.deltas=c(.01,.01),sl.defaults=c(.2,.8))
 slider(obj.name="p.old",obj.value=slider(no=1))
}
print.of.p.and.q()
}

# example 4, rotating a surface
if(interactive()){
## This example cannot be run by examples() but should work in an interactive R session
R.veil.in.the.wind<-function(){
  # Mark Hempelmann / Peter Wolf
  par(bg="blue4", col="white", col.main="white", 
      col.sub="white", font.sub=2, fg="white") # set colors and fonts
  refresh.code<-function(...){
    samp        <- function(N,D) N*(1/4+D)/(1/4+D*N) 
    z<-outer(seq(1, 800, by=10), seq(.0025, 0.2, .0025)^2/1.96^2, samp) # create 3d matrix
    h<-100 
    z[10:70,20:25]<-z[10:70,20:25]+h; z[65:70,26:45]<-z[65:70,26:45]+h
    z[64:45,43:48]<-z[64:45,43:48]+h; z[44:39,26:45]<-z[44:39,26:45]+h
    x<-26:59; y<-11:38; zz<-outer(x,y,"+"); zz<-zz*(65<zz)*(zz<73)
    cz<-10+col(zz)[zz>0];rz<-25+row(zz)[zz>0]; z[cbind(cz,rz)]<-z[cbind(cz,rz)]+h
    theta<-slider(no=1); phi<-slider(no=2)
    persp(x=seq(1,800,by=10),y=seq(.0025,0.2,.0025),z=z,theta=theta,phi=phi, 
          scale=T, shade=.9, box=F, ltheta = 45,
          lphi = 45, col="aquamarine", border="NA",ticktype="detailed")   
  }
  slider(refresh.code, c("theta", "phi"), c(0, 0),c(360, 360),c(.2, .2),c(85, 270)  )
}
R.veil.in.the.wind()
}