Develop

src/pyplot_module.F90

@@ -58,6 +58,7 @@ module pyplot_module
         private
 
         character(len=:), allocatable :: str !! string buffer
+        integer :: str_len = 0 !! current length of `str`
 
         character(len=1) :: raw_str_token = ' ' !! will be 'r' if using raw strings
 
@@ -91,6 +92,7 @@ module pyplot_module
         procedure, public :: add_bar       !! add a barplot to pyplot instance
         procedure, public :: add_imshow    !! add an image plot (using `imshow`)
         procedure, public :: add_hist      !! add a histogram plot to pyplot instance
+        procedure, public :: add_text      !! add text annotation to pyplot instance
         procedure, public :: savefig       !! save plots of pyplot instance
         procedure, public :: showfig       !! show plots of pyplot instance
         procedure, public :: destroy       !! destroy pyplot instance
@@ -114,6 +116,7 @@ subroutine destroy(me)
 
     class(pyplot),intent(inout) :: me !! pyplot handler
 
+    me%str_len = 0
     if (allocated(me%str))      deallocate(me%str)
     if (allocated(me%real_fmt)) deallocate(me%real_fmt)
 
@@ -136,22 +139,36 @@ subroutine add_str(me,str)
     integer :: n_str !! length of input `str`
     character(len=:),allocatable :: tmp !! tmp string for building the result
 
-    ! original
-    !me%str = me%str//str//new_line(' ')
-
     if (len(str)==0) return
 
+    ! original
+    !me%str = me%str//str//new_line(' ')
     ! the above can sometimes cause a stack overflow in the
     ! intel Fortran compiler, so we replace with this:
     if (allocated(me%str)) then
-        n_old = len(me%str)
-        n_str = len(str)
-        allocate(character(len=n_old+n_str+1) :: tmp)
-        tmp(1:n_old) = me%str
-        tmp(n_old+1:) = str//new_line(' ')
-        call move_alloc(tmp, me%str)
+
+        ! if there is room in the current string, then
+        ! insert str into it. otherwise, allocate a new string
+        ! with enough room and move the old string into it before adding str.
+
+        if (me%str_len + len(str) + 1 <= len(me%str)) then
+            me%str(me%str_len+1:me%str_len+len(str)) = str
+            me%str_len = me%str_len + len(str)
+            me%str(me%str_len+1:me%str_len+1) = new_line(' ')
+            me%str_len = me%str_len + 1
+        else
+            n_old = me%str_len
+            n_str = len(str)
+            ! double size to avoid too many allocations
+            allocate(character(len=2*(n_old+n_str)) :: tmp)
+            tmp(1:n_old) = me%str
+            tmp(n_old+1:) = str//new_line(' ')
+            call move_alloc(tmp, me%str)
+            me%str_len = n_old + n_str + 1
+        end if
     else
         allocate(me%str, source = str//new_line(' '))
+        me%str_len = len(me%str)
     end if
 
     end subroutine add_str
@@ -1099,6 +1116,107 @@ subroutine add_imshow(me, x, xlim, ylim, istat)
     end subroutine add_imshow
 !*****************************************************************************************
 
+!*****************************************************************************************
+!> author: Jacob Williams
+!
+! Add a text annotation to the plot.
+!
+!### Example
+!```fortran
+!  call plt%add_text(5.0_wp, 10.0_wp, 'Peak', fontsize=12, color='red', &
+!                    horizontalalignment='center', verticalalignment='bottom')
+!```
+
+    subroutine add_text(me, x, y, txt, fontsize, color, horizontalalignment, &
+                        verticalalignment, rotation, alpha, fontweight, &
+                        fontstyle, istat)
+
+    class(pyplot),    intent(inout)        :: me                    !! pyplot handler
+    real(wp),         intent(in)           :: x                     !! x position in data coordinates
+    real(wp),         intent(in)           :: y                     !! y position in data coordinates
+    character(len=*), intent(in)           :: txt                   !! text string to display
+    integer,          intent(in), optional :: fontsize              !! font size
+    character(len=*), intent(in), optional :: color                 !! text color
+    character(len=*), intent(in), optional :: horizontalalignment   !! horizontal alignment: 'left', 'center', 'right'
+    character(len=*), intent(in), optional :: verticalalignment     !! vertical alignment: 'top', 'center', 'bottom', 'baseline'
+    real(wp),         intent(in), optional :: rotation              !! rotation angle in degrees
+    real(wp),         intent(in), optional :: alpha                 !! transparency (0.0 to 1.0)
+    character(len=*), intent(in), optional :: fontweight            !! 'normal', 'bold', 'heavy', 'light', 'ultrabold', 'ultralight'
+    character(len=*), intent(in), optional :: fontstyle             !! 'normal', 'italic', 'oblique'
+    integer,          intent(out),optional :: istat                 !! status output (0 means no problems)
+
+    character(len=:), allocatable :: xstr              !! x value stringified
+    character(len=:), allocatable :: ystr              !! y value stringified
+    character(len=:), allocatable :: txt_str           !! plot command string
+    character(len=:), allocatable :: rotation_str      !! rotation value stringified
+    character(len=:), allocatable :: alpha_str         !! alpha value stringified
+    character(len=max_int_len)    :: fontsize_str      !! fontsize value stringified
+
+    if (allocated(me%str)) then
+
+        if (present(istat)) istat = 0
+
+        ! convert coordinates to strings
+        call real_to_string(x, me%real_fmt, xstr)
+        call real_to_string(y, me%real_fmt, ystr)
+
+        ! build the text command
+        txt_str = 'ax.text('//xstr//', '//ystr//', '//&
+                  trim(me%raw_str_token)//'"'//trim(txt)//'"'
+
+        ! add optional parameters
+        if (present(fontsize)) then
+            call optional_int_to_string(fontsize, fontsize_str, '10')
+            txt_str = txt_str//', fontsize='//trim(fontsize_str)
+        end if
+
+        if (present(color)) then
+            txt_str = txt_str//', color='//trim(me%raw_str_token)//'"'//trim(color)//'"'
+        end if
+
+        if (present(horizontalalignment)) then
+            txt_str = txt_str//', horizontalalignment='//trim(me%raw_str_token)//'"'//&
+                      trim(horizontalalignment)//'"'
+        end if
+
+        if (present(verticalalignment)) then
+            txt_str = txt_str//', verticalalignment='//trim(me%raw_str_token)//'"'//&
+                      trim(verticalalignment)//'"'
+        end if
+
+        if (present(rotation)) then
+            call real_to_string(rotation, me%real_fmt, rotation_str)
+            txt_str = txt_str//', rotation='//rotation_str
+        end if
+
+        if (present(alpha)) then
+            call real_to_string(alpha, me%real_fmt, alpha_str)
+            txt_str = txt_str//', alpha='//alpha_str
+        end if
+
+        if (present(fontweight)) then
+            txt_str = txt_str//', fontweight='//trim(me%raw_str_token)//'"'//&
+                      trim(fontweight)//'"'
+        end if
+
+        if (present(fontstyle)) then
+            txt_str = txt_str//', style='//trim(me%raw_str_token)//'"'//&
+                      trim(fontstyle)//'"'
+        end if
+
+        txt_str = txt_str//')'
+
+        ! add the text command
+        call me%add_str(txt_str)
+
+    else
+        if (present(istat)) istat = -1
+        write(error_unit,'(A)') 'Error in add_text: pyplot class not properly initialized.'
+    end if
+
+    end subroutine add_text
+!*****************************************************************************************
+
 !*****************************************************************************************
 !> author: Alexander Sandrock
 !
@@ -1451,7 +1569,7 @@ subroutine execute(me, pyfile, istat, python, wait)
         end if
 
         !write to the file:
-        write(iunit, '(A)') me%str
+        write(iunit, '(A)') me%str(1:me%str_len)
 
         !to ensure that the file is there for the next
         !command line call, we have to close it here.

test/color_test.f90

@@ -9,7 +9,7 @@ program color_test
     implicit none
 
     type(pyplot) :: plt   !! pytplot handler
-    integer :: istat
+    integer :: istat, i
     real(wp), parameter :: F(3) = [0.4510d0, 0.3098d0, 0.5882d0] ! Fortran-lang color
     real(wp), parameter :: Y(3) = [0.9608d0, 0.8157d0, 0.0118d0] ! Yellow
 
@@ -22,8 +22,14 @@ program color_test
 
     call plt%initialize(figsize=[20,10],title='color test')
 
-    call plt%add_plot(Ax,Ay,label='',linestyle='o',markersize=5,color=F)
-    call plt%add_plot(Bx,By,label='',linestyle='o',markersize=5,color=Y)
+    call plt%add_plot(Ax,Ay,label='',linestyle='o',markersize=50,color=F)
+    call plt%add_plot(Bx,By,label='',linestyle='o',markersize=50,color=Y)
+
+    do i = 1, 3
+        call plt%add_text(Ax(i), Ay(i), "F", fontsize=40, color="white", &
+                            horizontalalignment="center", verticalalignment="center", &
+                            istat=istat)
+    end do
 
     call plt%savefig(testdir//'color_test.png',&
                      pyfile=testdir//'color_test.py',istat=istat)

test/text_test.f90

@@ -0,0 +1,86 @@
+!*****************************************************************************************
+!> author: Jacob Williams
+!  license: BSD
+!
+!  Test of the add_text routine.
+
+    program text_test
+
+    use pyplot_module
+    use iso_fortran_env, only: wp => real64
+
+    implicit none
+
+    type(pyplot) :: plt
+    real(wp), dimension(100) :: x, y
+    real(wp) :: pi
+    integer :: i
+    integer :: istat
+
+    pi = acos(-1.0_wp)
+
+    ! Generate some data
+    do i = 1, 100
+        x(i) = real(i-1, wp) * 2.0_wp * pi / 99.0_wp
+        y(i) = sin(x(i))
+    end do
+
+    ! Initialize the plot
+    call plt%initialize(grid=.true., xlabel='x', ylabel='sin(x)', &
+                        title='Text Annotation Demo', &
+                        legend=.false., figsize=[10,6])
+
+    ! Add the main plot
+    call plt%add_plot(x, y, label='sin(x)', linestyle='b-', linewidth=2)
+
+    ! Add various text annotations with different styles
+    call plt%add_text(pi/2.0_wp, 1.0_wp, 'Peak at π/2', &
+                      fontsize=12, &
+                      color='red', &
+                      horizontalalignment='center', &
+                      verticalalignment='bottom', &
+                      istat=istat)
+
+    call plt%add_text(3.0_wp*pi/2.0_wp, -1.0_wp, 'Minimum at 3π/2', &
+                      fontsize=12, &
+                      color='blue', &
+                      horizontalalignment='center', &
+                      verticalalignment='top', &
+                      istat=istat)
+
+    call plt%add_text(pi, 0.0_wp, 'Zero crossing', &
+                      fontsize=10, &
+                      color='green', &
+                      rotation=45.0_wp, &
+                      horizontalalignment='left', &
+                      verticalalignment='bottom', &
+                      istat=istat)
+
+    call plt%add_text(0.5_wp, -0.8_wp, 'Bold text', &
+                      fontsize=14, &
+                      color='purple', &
+                      fontweight='bold', &
+                      istat=istat)
+
+    call plt%add_text(5.0_wp, 0.5_wp, 'Italic text', &
+                      fontsize=11, &
+                      color='orange', &
+                      fontstyle='italic', &
+                      istat=istat)
+
+    call plt%add_text(4.0_wp, -0.5_wp, 'Semi-transparent', &
+                      fontsize=10, &
+                      color='black', &
+                      alpha=0.5_wp, &
+                      istat=istat)
+
+    ! Save the figure
+    call plt%savefig('test/text_test.png', istat=istat)
+
+    if (istat /= 0) then
+        write(*,*) 'Error saving figure'
+    else
+        write(*,*) 'Figure saved successfully: test/text_test.png'
+    end if
+
+    end program text_test