R/topoplot.palette.R

In erpR: Event-Related Potentials (ERP) Analysis, Graphics and Utility Functions

topoplot.palette<-function(cols, pos = c(0.5,0.5), p.width=0.2, p.height=0.8, horizontal = FALSE, rev= FALSE, palette.lwd=2, palette.bord="black", palette.lim = c(-5,5), draw.labels=TRUE, lab.dist = 1, lab.cex = 1, lab.font = 1, lab.family = "", measure="microvolts", detailed.labels = NULL)
{
  # det.labels gives you the opportunity to specify the labels as you want (also including formula or others)
  
  # reverse vector if required
  if (rev == T){
    cols=rev(cols)
    palette.lim=rev(palette.lim)
  }
  
  # some adjustments to palette.lim
  palette.lim[palette.lim>0]=paste("+", palette.lim[palette.lim>0], sep="")
  
  #find coordinates
  xlim=par("usr")[1:2]
  ylim=par("usr")[3:4]
  
  tot.x=as.numeric(dist(xlim))
  tot.y=as.numeric(dist(ylim))
  
  #calculate the position of the center of the rectangle (x.axis)
  pos.x=tot.x*pos[1]+xlim[1]
  
  #calculate the position of the center of the rectangle (y.axis)
  pos.y=tot.y*pos[2]+ylim[1]
  
  ### find rectangle dimensions
  
  rect.length=p.width*tot.x
  rect.height=p.height*tot.y
  
  x0rect=pos.x-(rect.length/2)	
  x1rect=pos.x+(rect.length/2)
  
  y0rect=pos.y-(rect.height/2)
  y1rect=pos.y+(rect.height/2)
  
  # draw palette horizontally
  
  if (horizontal==TRUE){
    
    #find palette steps length
    p.steps.length=rect.length/length(cols)	
    
    for (i in 0:(length(cols)-1)){
      
      p.xcoord=c(x0rect+i*p.steps.length, x0rect+i*p.steps.length+p.steps.length, x0rect+i*p.steps.length+p.steps.length, x0rect+i*p.steps.length)		
      p.ycoord=c(y0rect, y0rect, y1rect, y1rect)
      polygon(p.xcoord,p.ycoord, col=cols[i+1], border=cols[i+1])
      
    }
    
    #draw rectangle
    polygon(c(x0rect, x1rect, x1rect, x0rect), c(y0rect, y0rect, y1rect, y1rect), border = palette.bord, lwd = palette.lwd)
    
    #### draw labels when plot is horizontal
    
    if (draw.labels == TRUE){
      
      # calculate the distance between the label and the rectangle. 
      lab.x.dist=tot.x*lab.dist/100
      
      if (measure == "microvolts") {
        up_lab = bquote(paste(.(palette.lim[1]), " ",  mu, "V"))
        down_lab = bquote(paste(.(palette.lim[2]), " ",  mu, "V"))
        
      } else {
        
        up_lab = paste(palette.lim[1], measure, sep=" ")
        down_lab = paste(palette.lim[2], measure, sep=" ")
      }
      
      ## override previous labels in the case detailed labels are specified
      if (!is.null(detailed.labels)){
        up_lab = detailed.labels[[1]]
        down_lab = detailed.labels[[2]]
        
      }
      
      text((x0rect - lab.x.dist) ,  pos.y, labels= up_lab, pos = 2, cex = lab.cex, font = lab.font, family = lab.family) 
      # notice how I retrieve the value of a variable with .()
      text((x1rect + lab.x.dist) ,  pos.y, labels= down_lab, pos = 4, cex = lab.cex, font = lab.font, family = lab.family)
      
      
    }
    
    
  }
  
  
  # draw palette vertically
  
  if (horizontal==FALSE){
    #find palette steps length
    p.steps.length=rect.height/length(cols)	
    
    for (i in 0:(length(cols)-1)){
      
      p.ycoord=c(y0rect+i*p.steps.length, y0rect+i*p.steps.length+p.steps.length, y0rect+i*p.steps.length+p.steps.length, y0rect+i*p.steps.length)		
      p.xcoord=c(x0rect, x0rect, x1rect, x1rect)
      polygon(p.xcoord,p.ycoord, col=cols[i+1], border=cols[i+1])
      
    }
    
    #draw rectangle when it is vertical
    polygon(c(x0rect, x1rect, x1rect, x0rect), c(y0rect, y0rect, y1rect, y1rect), border = palette.bord, lwd = palette.lwd)
    
    #### draw labels when plot is vertical
    if (draw.labels == TRUE){
      
      # calculate the distance between the label and the rectangle. 
      lab.y.dist=tot.y*lab.dist/50
      
      if (measure == "microvolts"){
        up_lab = bquote(paste(.(palette.lim[1]), " ",  mu, "V"))
        down_lab = bquote(paste(.(palette.lim[2]), " ",  mu, "V"))
        
      } else {
        up_lab = paste(palette.lim[1], measure, sep=" ")
        down_lab = paste(palette.lim[2], measure, sep=" ")
      }
      
      ## override previous labels in the case detailed labels are specified
      if (!is.null(detailed.labels)[1]){
        up_lab = detailed.labels[[1]]
        down_lab = detailed.labels[[2]]
        
      }
      
      text(pos.x , y0rect-lab.y.dist, labels= up_lab,  cex = lab.cex, font = lab.font, family = lab.family) 
      # notice how I retrieve the value of a variable with .()
      text(pos.x, y1rect+lab.y.dist, labels= down_lab,  cex = lab.cex, font = lab.font,  family = lab.family)
      
      invisible(lab.y.dist)
      
    }
    
    
  }
  
}