library("tcltk")
#source("hyad.r")
#attach(hip[HyadFilter,])
#logL = (15 - Vmag - 5 * log10(Plx)) / 2.5
n = length(logL)
doit = function(...) {
  alpha = as.numeric(tclvalue(tva))
  beta = as.numeric(tclvalue(tvb))
  plot(B.V,logL)
  abline(a=alpha,b=beta)

  y = cbind(logL,alpha+beta*B.V)
  err = y%*%c(1,-1)
  col = ifelse(err<0,"blue","red")
  tclvalue(labelText)  = sum(err^2)

  for(i in 1:n) {
    lines(x[i,],y[i,],col=col[i])
  }
}

x = cbind(B.V,B.V)
tt = tktoplevel()
labelText <- tclVar("This is a text label")
laba <- tklabel(tt,text="a=")
labb <- tklabel(tt,text="b=")
label2 <- tklabel(tt,text="Sum of sqd err=")
label1 <- tklabel(tt,text=tclvalue(labelText))
tkconfigure(label1,textvariable=labelText)

tva = tclVar(0.01)
tvb = tclVar(0.01)
scla = tkscale(tt, comm=doit, from=0.0, to=5, reso=0.1,
orient="horizontal", variable=tva)
sclb = tkscale(tt, comm=doit, from=-3, to=2, reso=0.1,
orient="horizontal", variable=tvb)
butt = tkbutton(tt,text="Done!", comm=function() tkdestroy(tt))
tkpack(laba,scla,labb,sclb,label2,label1,butt)