draw.default           package:wavethresh           R Documentation

_D_r_a_w _p_i_c_t_u_r_e _o_f _a _w_a_v_e_l_e_t _o_r _s_c_a_l_i_n_g _f_u_n_c_t_i_o_n.

_D_e_s_c_r_i_p_t_i_o_n:

     This function can produce pictures of one- or two-dimensional
     wavelets or scaling functions at various levels of resolution.

_U_s_a_g_e:

     draw.default(filter.number = 10, family = "DaubLeAsymm", resolution = 8192,
             verbose = FALSE, plot.it = TRUE, main = "Wavelet Picture", sub = zwd$
             filter$name, xlab = "x", ylab = "psi", dimension = 1, twodplot
              = persp, enhance = TRUE, efactor = 0.05, scaling.function = FALSE, 
             ...)

_A_r_g_u_m_e_n_t_s:

filter.number : This selects the index number of the wavelet or scaling
          function you want to draw (from within the wavelet family).

  family: specifies the family of wavelets that you want to draw. The
          options are "DaubExPhase" and "DaubLeAsymm".

resolution : specifies the resolution that the wavelet or scaling
          function is computed to. It does not necessarily mean that
          you see all of these points as if the enhance option is TRUE
          then some function points are omitted.

 verbose: Controls the printing of "informative" messages whilst the
          computations progress. Such messages are generally annoying
          so it is turned off by default.

plot.it : If TRUE then this function attempts to plot the function
          (i.e. draw it on a graphics device which should be active).
          If FALSE then this function returns the coordinates of the
          object that would have been plotted.

    main: a main title for the plot

     sub: a subtitle for the plot.

    xlab: a label string for the x-axis

    ylab: a label string for the y-axis

dimension : whether to make a picture of the one-dimensional wavelet or
          the two-dimensional wavelet.

twodplot : which function to use to produce the two-dimensional plot if
          dimension=2. The function you supply should accept data just
          like the contour or persp functions supplied with S-Plus.

 enhance: If this argument is TRUE then the plot is enhanced in the
          following way. Many of Daubechies' compactly supported
          wavelets are near to zero on a reasonable proportion of their
          support. So if such a wavelet is plotted quite a lot of it
          looks to be near zero and the interesting detail seems quite
          small. This function chooses a nice range on which to plot
          the central parts of the function and the function is plotted
          on this range.

 efactor: Variable which controls the range of plotting associated with
          the enhance option above. Any observations smaller than
          efactor times the range of the absolute function values are
          deemed to be too small. Then the largest range of
          ``non-small'' values is selected to be plotted.

scaling.function : If this argument is TRUE the scaling function is
          plotted otherwise the mother wavelet is plotted.

     ...: other arguments you can supply to the plot routine embedded
          within this function.

_D_e_t_a_i_l_s:

     The algorithm underlying this function produces a picture of the
     wavelet or scaling function by first building a 'wavelet
     decomposition' object of the correct size (i.e. 'correct
     resolution') and setting all entries equal to zero. Then one
     coefficient at a carefully selected resolution level is set to one
     and the decomposition is inverted to obtain a picture of the
     wavelet.

_V_a_l_u_e:

     If 'plot.it=FALSE' then usually a list containing coordinates of
     the object that _would_ have been plotted is returned. This can be
     useful if you don't want S-Plus to do the plotting or you wish to
     use the coordinates of the wavelets for other purposes.

_R_E_L_E_A_S_E:

     Version 3.5.3 Copyright Guy Nason 1994

_N_o_t_e:

     A plot is produced of the wavelet or scaling function if
     'plot.it=TRUE'.

_S_e_e _A_l_s_o:

     'filter.select', 'wd', 'wd.object', 'wr', 'wr.wd'.

_E_x_a_m_p_l_e_s:

     #
     # First make sure that your favourite graphics device is open
     # otherwise S-Plus will complain.
     #
     # Let's draw a one-dimensional Daubechies least-asymmetric wavelet
     # N=10
     #
     #draw.default(filter.number=10, family="DaubLeAsymm")
     #
     # Wow. What a great picture!
     #
     # Now how about a one-dimensional Daubechies extremal-phase scaling function
     # with N=2
     #
     #draw.default(filter.number=2, family="DaubExPhase")
     #
     # Excellent! Now how about a two-dimensional Daubechies least-asymmetric
     # N=6 wavelet
     #
     # N.b. we'll also reduce the resolution down a bit. If we used the default
     # resolution of 8192 this would be probably too much for most computers.
     #
     #draw.default(filter.number=6, family="DaubLeAsymm", dimension=2, res=256)
     #
     # What a pretty picture!

