WIP

apps/find_plane.lua

@@ -1,6 +1,10 @@
 local apps       = require 'apps.apps'
+local matrix     = require 'matrix'
+local advice     = require 'advice'
 local ask        = require('dialog.input').display_sync
 local choice     = require('dialog.choice').display_sync
+local choice     = require('dialog.choice').display_sync
+local matrix_ed  = require('rpn.matrixeditor').display_sync
 local expr       = require 'expressiontree'
 local sym        = require 'ti.sym'
 
@@ -31,6 +35,7 @@ local function ask_vector(title, dim)
    end
 end
 
+-- Compute plane equation from 3 points
 local function run_plane_3pt(stack)
    local pts = {}
    for i = 1, 3 do
@@ -52,15 +57,25 @@ local function run_plane_3pt(stack)
    local res_p = "x = " .. table_to_vec(a) .. " + s*" .. ab .. " + t*" .. ac
    local res_n = "(x - " .. table_to_vec(a) .. ") " .. sym.CDOT .. " " .. n
 
-   local store = choice { title = 'Results', items = {
-      { title = 'E: ' .. res_c, align = -1, result = 'c', seq = {'c'} },
+   local action = choice { title = 'Results', items = {
+      { title = 'E: ' .. res_c, align = -1, result = 'c' },
       { title = 'E: ' .. res_p, align = -1, result = 'p' },
       { title = 'E: ' .. res_n, align = -1, result = 'n' },
-      { title = 'Exit', result = false},
+      { title = 'Store...', result = 'store' },
+      { title = 'Exit', result = 'done' },
    }}
 
-   if store == 'c' then
+   if action == 'store' then
+      local sym = ask { title = 'Variable', text = 'E1' }
+      if sym and #sym > 0 then
+         stack:push_infix(res_c)
+         stack:push_infix(sym)
+         stack:push_operator('=:')
+      end
+   elseif action == 'c' then
       stack:push_infix(res_c)
+   elseif action == 'done' then
+      return
    end
 end
 
@@ -71,5 +86,83 @@ local function run_angle_2vec(stack)
    stack:push_infix("arccos(dotp(" .. a .. "," .. b .. ")/(norm(" .. a .. "*norm(" .. b ..  "))")
 end
 
+local function run_dist_2pt(stack)
+   local a = table_to_vec(ask_vector("Point A"))
+   local b = table_to_vec(ask_vector("Point B"))
+
+   stack:push_infix("norm(" .. b .. "-" .. a .. ")")
+end
+
+local function run_2lines(ctrl, stack)
+   local mat = matrix.new(4, 5)
+   mat:set(0,0," ")
+   mat:set(1,2,"p1")
+   mat:set(1,3,"d1")
+   mat:set(1,4,"p2")
+   mat:set(1,5,"d2")
+   mat:set(2,1,"x")
+   mat:set(3,1,"y")
+   mat:set(4,1,"z")
+
+   local function get_line(mat, m, n)
+      local o = {
+         mat:get(m + 0, n),
+         mat:get(m + 1, n),
+         mat:get(m + 2, n),
+      }
+      local d = {
+         mat:get(m + 0, n + 1),
+         mat:get(m + 1, n + 1),
+         mat:get(m + 2, n + 1),
+      }
+      return o, d
+   end
+
+   local function vec_str(l)
+      return string.format("[[%s,%s,%s]]", table.unpack(l))
+   end
+
+   local function setup_dlg(dlg)
+      local grid = dlg.grid
+      grid:set_header(1,1)
+      grid:set_selection(2,2)
+   end
+
+   local res = matrix_ed(ctrl, mat, setup_dlg)
+   if res then
+      local p1, d1 = get_line(2, 2)
+      local p2, d2 = get_line(2, 4)
+      local vp1, vd1 = vec_str(p1), vec_str(d1)
+      local vp2, vd2 = vec_str(p2), vec_str(d2)
+
+      local eq1 = vp1 .. "+a*".. vd1
+      local eq2 = vp2 .. "+b*".. vd2
+
+      local isection = "solve(" .. eq1 .. "=" .. eq2 .. ",a,b)"
+      local parallel = "solve(" .. vd1 .. "=t*" .. vd2 .. ",t)"
+      local n = math.evalStr("crossp(" .. vd1 .. "," .. vd2 .. ")")
+      local n1 = math.evalStr("crossp(" .. vd1 .. "," .. n .. ")")
+      local n2 = math.evalStr("crossp(" .. vd2 .. "," .. n .. ")")
+      local nearest1 = string.format("%s+(dotp(%s-%s,%s)/dotp(%s,%s))*%s",
+        vp1, vp2, vp1, n2, vd1, n2, vd1)
+      local nearest2 = string.format("%s+(dotp(%s-%s,%s)/dotp(%s,%s))*%s",
+        vp2, vp1, vp2, n1, vd2, n1, vd2)
+      local distance = "norm(" .. nearest1 .. "-" .. nearest2 ..")"
+
+      local r_isection = math.evalStr(isection)
+      local r_parallel = math.evalStr(parallel)
+      print(r_isection)
+      print(r_parallel)
+
+      if r_isection ~= 'false' then
+         return
+      else
+         return
+      end
+   end
+end
+
 apps.add('plane - 3pt', 'Plane - 3 Points', run_plane_3pt)
-apps.add('angle - 2vec', 'Angle - 2 Vectors', run_angle_2vec)
+apps.add('angle - 2vec', 'Angle - 2 Vectors', run_angle_2vec)
+apps.add('dist - 2pt',   'Dist. - 2 Points', run_dist_2pt)
+apps.add('2line',   '2line', run_2lines)