Merge pull request #508 from plotly/fix-json-precision

Fix precision when converting to json and add more test cases

Author: robertoffmoura

plotly/plotly_aux/Test_m2json.m

@@ -1,22 +1,36 @@
 classdef Test_m2json < matlab.unittest.TestCase
     methods (Test)
+        function testLowPrecisionInRange0to10(tc)
+            values = 1 + (1:5) + 0.234;
+            expected = "[2.234,3.234,4.234,5.234,6.234]";
+            tc.verifyEqual(string(m2json(values)), expected);
+        end
+
         function testInRange0to10(tc)
             values = 1 + (1:5) + 0.23456789;
-            expected = "[2.235,3.235,4.235,5.235,6.235]";
+            expected = "[2.23456789,3.23456789,4.23456789,5.23456789," ...
+                    + "6.23456789]";
             tc.verifyEqual(string(m2json(values)), expected);
         end
 
         function test2dArrayInRange0to10(tc)
-            values = 1 + (1:5) + (0:1)' + 0.23456789;
-            expected = "[[2.235,3.235,4.235,5.235,6.235]," ...
-                    + "[3.235,4.235,5.235,6.235,7.235]]";
+            values = 1 + (1:5) + (0:1)' + 0.234;
+            expected = "[[2.234,3.234,4.234,5.234,6.234]," ...
+                    + "[3.234,4.234,5.234,6.234,7.234]]";
+            tc.verifyEqual(string(m2json(values)), expected);
+        end
+
+        function testLowPrecisionInRange1e6to1e5(tc)
+            values = 1e-6 * (1 + (1:5) + 0.234);
+            expected = "[2.234e-06,3.234e-06,4.234e-06,5.234e-06," ...
+                    + "6.234e-06]";
             tc.verifyEqual(string(m2json(values)), expected);
         end
 
         function testInRange1e6to1e5(tc)
             values = 1e-6 * (1 + (1:5) + 0.23456789);
-            expected = "[2.235e-06,3.235e-06,4.235e-06,5.235e-06," ...
-                    + "6.235e-06]";
+            expected = "[2.23456789e-06,3.23456789e-06,4.23456789e-06," ...
+                    + "5.23456789e-06,6.23456789e-06]";
             tc.verifyEqual(string(m2json(values)), expected);
         end
 
@@ -36,21 +50,28 @@ function testInRange1e14Plus1e7Plus0to1(tc)
 
         function testLogScaledVariables(tc)
             values = 1e14 + 10.^(1:5) + 0.23456789;
-            expected = "[1e+14,1.000000000001e+14,1.00000000001e+14," ...
-                    + "1.0000000001e+14,1.000000001e+14]";
+            expected = "[100000000000010,100000000000100," ...
+                    + "100000000001000,100000000010000,100000000100000]";
+            tc.verifyEqual(string(m2json(values)), expected);
+        end
+
+        function testLowPrecisionInRangeMinus10to0(tc)
+            values = -(1 + (1:5) + 0.234);
+            expected = "[-2.234,-3.234,-4.234,-5.234,-6.234]";
             tc.verifyEqual(string(m2json(values)), expected);
         end
 
         function testInRangeMinus10to0(tc)
             values = -(1 + (1:5) + 0.23456789);
-            expected = "[-2.235,-3.235,-4.235,-5.235,-6.235]";
+            expected = "[-2.23456789,-3.23456789,-4.23456789," ...
+                    + "-5.23456789,-6.23456789]";
             tc.verifyEqual(string(m2json(values)), expected);
         end
 
         function testInRangeMinus1e5toMinus1e6(tc)
             values = -1e-6 * (1 + (1:5) + 0.23456789);
-            expected = "[-2.235e-06,-3.235e-06,-4.235e-06,-5.235e-06," ...
-                    + "-6.235e-06]";
+            expected = "[-2.23456789e-06,-3.23456789e-06," ...
+                    + "-4.23456789e-06,-5.23456789e-06,-6.23456789e-06]";
             tc.verifyEqual(string(m2json(values)), expected);
         end
 

plotly/plotly_aux/m2json.m

@@ -5,11 +5,10 @@
         valstr = cell2json(val);
     elseif isa(val, "numeric")
         sz = size(val);
-        numDigits = max(arrayfun(@getPrecision, val));
         if isa(val,"single")
-            numDigits = min(7, numDigits);
+            numDigits = 7;
         else
-            numDigits = min(15, numDigits);
+            numDigits = 15;
         end
         fmt = sprintf("%%.%ig", numDigits);
         if sum(sz>1)>1 % 2D or higher array
@@ -61,7 +60,3 @@
         warning("Failed to m2json encode class of type: %s", class(val));
     end
 end
-
-function numDigits = getPrecision(val)
-    numDigits = strlength(sprintf("%.15g", val));
-end