colorpanel              package:gplots              R Documentation

_G_e_n_e_r_a_t_e _a _s_m_o_o_t_h_l_y _v_a_r_y_i_n_g _s_e_t _o_f _c_o_l_o_r_s

_D_e_s_c_r_i_p_t_i_o_n:

     'colorpanel' generate a set of colors that varies smoothly.
     'redgreen', 'greenred', 'bluered', and  'redblue' generate
     red-black-green, green-black-red, red-white-blue, and
     blue-white-red colorbars, respectively. colors

_U_s_a_g_e:

     colorpanel(n, low, mid, high)
     redgreen(n)
     greenred(n)
     bluered(n)
     redblue(n)

_A_r_g_u_m_e_n_t_s:

       n: Desired number of color elements in the panel.

low, mid, high: Colors to use for the Lowest, middle, and highest
          values.

_D_e_t_a_i_l_s:

     The values for 'low, mid, high' can be given as color names
     ('red'), plot color index (2=red), and HTML-style RGB,
     ("#FF0000"=red). 

     The returned color panel will consist of 'n - floor(n/2)'
     HTML-style RGB elements which vary smoothly between 'low' and
     'mid', then  between 'mid' and 'high'.  Note that if 'n' is even,
     the color 'mid' will occur twice at the center of the sequence.

_V_a_l_u_e:

     Vector of HTML-style RGB colors.

_A_u_t_h_o_r(_s):

     Gregory R. Warnes Gregory_R_Warnes@groton.pfizer.com

_S_e_e _A_l_s_o:

     'colors '

_E_x_a_m_p_l_e_s:

     showpanel <- function(col)
     {
       image(z=matrix(1:100, ncol=1), col=col, xaxt="n", yaxt="n" )
     }

     par(mfrow=c(2,3))

     showpanel(colorpanel(8,"red","black","green"))
     # note the duplicatation of black at the center, using an odd
     # number of elements resolves this:
     showpanel(colorpanel(9,"red","black","green"))

     showpanel(greenred(64))
     showpanel(redgreen(64))
     showpanel(bluered(64))
     showpanel(redblue(64))

