Differences

This shows you the differences between two versions of the page.

--- curves [2020/07/30 12:50] – created atolstov
+++ curves [2022/05/24 08:52] (current) – [Get value from the curve via Lua] emozolyak
@@ Line 1: / Line 1: @@
+{{ network:menu-icon-curves.png?nolink&60|}}
 ======Curves======
+=====Introduction=====
+{{ :curve:function_machine2.png?nolink&200|}}
 Curve is a way to define output value from a pre-defined pair table of a discrete set of known data points. Such as standard or desired value.
-It can be represented as a black-box, where is some INPUT have corresponding OUTPUT.(svg)
+Curve can be represented as a function f, which is a blackbox, where is some **INPUT x** have corresponding **OUTPUT y** = f(x)
 Curve is using a piecewise linear interpolation, is a curve fitting which is a allow to using linear polynomials to construct new data points within the range of a discrete set of known data points.
@@ Line 21: / Line 23: @@
   * There is strict algebraic function and value should be calculated.
   * The function should be sequentually or time-to-time changed.
-<del>
-To define curve algebraically, it is linear equation of a line that passes through two given points used. It is also known as Linear interpolation between two known points.</del>
-To define curve algebraically, it is linear interpolation between two known points for every piece used. Its string reprentation is a JSON formatted linear polynomial factor "**k**", syllable "**b**" and function definition domain "**range**" values for every piece of a curve, so that inside the **range**  of INPUT value OUTPUT value can be calculated as\\  ''y = **k** × x + **b**''
+To define curve algebraically, it is linear interpolation between two known points for every piece used. Its string reprentation is a JSON formatted linear polynomial factor "**k**", syllable "**b**" and function definition domain "**range**" values for every piece of a curve, so that inside the **range**  of **INPUT x** value **OUTPUT y** value can be calculated as\\  ''y = **k**⋅x + **b**''
-For example:
+For example:\\
-(0 to 100 line; 0 1 0 1 / 24 hour ; temperature citoterm falling curve; sinus)
+At minimum it can be two points.\\
+{{ :curve:c1.png?direct&600 |}}\\
+Binary logic function.\\
+{{ :curve:c2.png?direct&600 |}}\\
+Table parameter definition\\
+{{ :curve:c3.png?direct&600 |}}\\
+Saturation function\\
+{{ :curve:c4.png?direct&600 |}}\\
+Algebraic defined calculated function. For example sin(x) with 6 points approximation.\\
+{{ :curve:c5.png?direct&600 |}}\\
-To get the OUTPUT value **y** from existing(pre-created) curve, you need:
+=====New curve creation=====
+Let's create a new curve. \\
+Click on "New curve" button.\\
+{{ :curve:curve_new.png?direct&600 |}}\\
+Type in a Title and go on the next tab ''Curve''\\
+{{ :curve:curve_tab.png?direct&600 |}}\\
+Optionally, you can check "Use the existing String register to store the curve parameters" to store it all the time in this register if you will.
+{{ :curve:c1_start.png?direct&600 |}}
+Here is a curve editor. There is a domain of a function definition, range of a function and every point X and Y coordinates.\\
+{{ :curve:curve_new_start.png?direct&600 |}}\\
+To create a new point click twice on a line. To remove it click with holding Alt button.\\
+{{ :curve:curve_new_click.png?direct&600 |}}\\
+Then you can both move point or specify its value using form in the right.\\
+{{ :curve:curve_new_move.png?direct&600 |}}\\
+At the end, when all the rest of parameters set let's look at the result . In our example it would more precise approximation of sin(x) with 7 point defined\\
+{{ :curve:c6.png?direct&600 |}}\\
+=====Select a curve to put in register=====
+To get the value you need:
+  - Have a curve
+  - Have a string register for dashboard element to put selected curve in it
+  - Optionally, have yet another string register for store that curve all the time
+Now, it is time to create a register with value type "String" for dashboard element.
+Then, create a new dashboard.
+{{ :curve:no_dashb.png?direct&600 |}}
+Click the "Add dashboard".
+{{ :curve:dash.png?direct&600 |}}
+Type in the Title and go on.
+{{ :curve:dash_vis_editor.png?direct&600 |}}
+Go to a visual editor.
+To do this, there is a dashboard element "Curve".
+{{ :curve:dash_element.png?direct&600 |}}
+Drag'n'drop it to create a new one.
+{{ :curve:dash_element_created.png?direct&600 |}}
+Pick a register to be used later in Lua script to get value.
+{{ :curve:dash_element_reg.png?direct&600 |}}
+Let's test it.
+Now, you need to put the curve to string register via dashboard.
+{{ :curve:dash_element_view_no_select.png?direct&600 |}}
+Click and select the one you want to pick. There is a icon for open curve editor.
+{{ :curve:dash_element_view_selector.png?direct&600 |}}
+There is a picked one.
+{{ :curve:dash_element_view_curve_1.png?direct&600 |}}
+ Let's check the register.
+{{ :curve:reg_filled_with_equat.png?direct&600 |}}
+=====Get value from the curve via Lua =====
+To get the **OUTPUT y value** from existing(pre-created) curve, you need:
   - a Lua script to work with string register and
   - include a Lua lib, which will provide access to that function.
@@ Line 36: / Line 98: @@
   - Call a GetCurveValue function and pass to it this ''**register**'' and INPUT ''**x**''.
+<code lua - curves.lib>
+--[[
+The function does curve conversion f(inputValue) = outputValue
+Example of a curve, having multiple ranges of kx + b, set in a register of a String type with Json
+[{"k":4.167,"b":0,"range":[0,3]},{"k":0,"b":12.5,"range":[3,27]},{"k":-4.167,"b":125,"range":[27,30]}]
+--]]
+function getCurveValue (curveReg, inputValue)
+    local s, e = 1, 2                           -- start & end indexes of the subranges
-<code lua - curves.lib>
+    local tab = cjson.decode( R(curveReg) )
-function GetCurveValue ( curve_register, x_to_find_y  )
+    local outputValue, stickOutflag
-    --[[
-    --Curve handler
-    INPUT:
-        Put curve register as first argument and X coordinate as second.
-    OUTPUT:
-        Get as result status if it is inside curve range of outside(false) and the Y value as second output argument
-    EXAMPLE:
-        curve_status, value = GetCurveValue( "curve_for_current_hour", current_hour )
-    --]]
+    for _, sub_ in ipairs(tab) do
-    table = cjson.decode( R ( curve_register ) )
+        if ( (sub_.range[s] <= inputValue) and (inputValue < sub_.range[e]) ) then
-    -- inRangeCurve( table, x_to_find_y )
+            return (inputValue * sub_.k + sub_.b), nil                             -- normal sequence
-    for _, value in ipairs( table ) do --piecewise handler inside range of the curve
-        if ( value.range[1] <= x_to_find_y and x_to_find_y < value.range[2] ) then
-            -- in_range_status, index_curve_piece, y = true, index, curveLinearCalc( x_to_find_y, value.k, value.b )
-            in_range_status, y = true, ( x_to_find_y * value.k + value.b )
-            return in_range_status, y
         end
     end
-    if  x_to_find_y < table[1].range[1] then -- behaivior for outside left-sided
+    -- edge cases
-        -- in_range_status, index_curve_piece, y = false, 1, curveLinearCalc( table[1].range[1], table[1].k*0, table[1].b ) --table[1].b
+    if  (inputValue < tab[s].range[s]) then
-        in_range_status, index_curve_piece, y = false, 1, ( table[1].range[1] * table[1].k + table[1].b ) --table[1].b
+        outputValue = tab[s].range[s] * tab[s].k + tab[s].b
-        return in_range_status, y
+        stickOutflag = 1
-    elseif x_to_find_y > table[#table].range[2] then -- behaivior for outside right-sided
+    elseif (inputValue > tab[#tab].range[e]) then
-        -- in_range_status, index_curve_piece, y = false,#table,curveLinearCalc( table[#table].range[2], table[#table].k, table[#table].b ) --table[#table].b
+        outputValue = tab[#tab].range[e] * tab[#tab].k + tab[#tab].b
-        in_range_status,  y = false,#table,( table[#table].range[2] * table[#table].k + table[#table].b)
+        stickOutflag = #tab
-        return in_range_status, y
     end
+    return outputValue, stickOutflag
-    return in_range_status, y
 end
 </code>
 Example of usage:
 <code lua - Getter>
 include "curves.lib"
 function main (userId)
+    local SAFE_VALUE = 10
-    local t = os.date("*t", os.time())
+    local curHour = tonumber( os.date("*t", os.time()).hour )
-    current_hour = tonumber(t.hour)
+    INFO("curHour "  .. curHour)
-    curve_status, y = GetCurveValue( "curve_for_current_hour", current_hour )
+    local y, valueOutOfRange = getCurveValue("curve_for_curHour", curHour)
-    WriteReg("value_for_current_hour", y)
+    if (not valueOutOfRange) then
+        W("value_for_curHour", y)  -- WriteReg
+    else
+        W("value_for_curHour", SAFE_VALUE)
+    end
 end
 </code>