ref #65, new formula functions: SKEW.P and SLOPE, remove no-required format default

6 files changed, 160 insertions, 35 deletions

diff --git a/calc.go b/calc.go
index a90bbc3..03d467b 100644
--- a/calc.go
+++ b/calc.go
@@ -640,7 +640,9 @@ type formulaFuncs struct {
 //    SIN
 //    SINH
 //    SKEW
+//    SKEW.P
 //    SLN
+//    SLOPE
 //    SMALL
 //    SQRT
 //    SQRTPI
@@ -8860,14 +8862,20 @@ func (fn *formulaFuncs) min(mina bool, argsList *list.List) formulaArg {
 	return newNumberFormulaArg(min)
 }
 
-// pearsonProduct is an implementation of the formula functions PEARSON and
-// RSQ.
+// pearsonProduct is an implementation of the formula functions PEARSON, RSQ
+// and SLOPE.
 func (fn *formulaFuncs) pearsonProduct(name string, argsList *list.List) formulaArg {
 	if argsList.Len() != 2 {
 		return newErrorFormulaArg(formulaErrorVALUE, fmt.Sprintf("%s requires 2 arguments", name))
 	}
-	array1 := argsList.Front().Value.(formulaArg).ToList()
-	array2 := argsList.Back().Value.(formulaArg).ToList()
+	var array1, array2 []formulaArg
+	if name == "SLOPE" {
+		array1 = argsList.Back().Value.(formulaArg).ToList()
+		array2 = argsList.Front().Value.(formulaArg).ToList()
+	} else {
+		array1 = argsList.Front().Value.(formulaArg).ToList()
+		array2 = argsList.Back().Value.(formulaArg).ToList()
+	}
 	if len(array1) != len(array2) {
 		return newErrorFormulaArg(formulaErrorNA, formulaErrorNA)
 	}
@@ -8898,7 +8906,10 @@ func (fn *formulaFuncs) pearsonProduct(name string, argsList *list.List) formula
 	if name == "RSQ" {
 		return newNumberFormulaArg(math.Pow(sum/math.Sqrt(deltaX*deltaY), 2))
 	}
-	return newNumberFormulaArg(sum / math.Sqrt(deltaX*deltaY))
+	if name == "PEARSON" {
+		return newNumberFormulaArg(sum / math.Sqrt(deltaX*deltaY))
+	}
+	return newNumberFormulaArg(sum / deltaX)
 }
 
 // PEARSON function calculates the Pearson Product-Moment Correlation
@@ -9268,16 +9279,19 @@ func (fn *formulaFuncs) RSQ(argsList *list.List) formulaArg {
 	return fn.pearsonProduct("RSQ", argsList)
 }
 
-// SKEW function calculates the skewness of the distribution of a supplied set
-// of values. The syntax of the function is:
-//
-//    SKEW(number1,[number2],...)
-//
-func (fn *formulaFuncs) SKEW(argsList *list.List) formulaArg {
+// skew is an implementation of the formula functions SKEW and SKEW.P.
+func (fn *formulaFuncs) skew(name string, argsList *list.List) formulaArg {
 	if argsList.Len() < 1 {
-		return newErrorFormulaArg(formulaErrorVALUE, "SKEW requires at least 1 argument")
+		return newErrorFormulaArg(formulaErrorVALUE, fmt.Sprintf("%s requires at least 1 argument", name))
+	}
+	mean := fn.AVERAGE(argsList)
+	var stdDev formulaArg
+	var count, summer float64
+	if name == "SKEW" {
+		stdDev = fn.STDEV(argsList)
+	} else {
+		stdDev = fn.STDEVP(argsList)
 	}
-	mean, stdDev, count, summer := fn.AVERAGE(argsList), fn.STDEV(argsList), 0.0, 0.0
 	for arg := argsList.Front(); arg != nil; arg = arg.Next() {
 		token := arg.Value.(formulaArg)
 		switch token.Type {
@@ -9300,11 +9314,43 @@ func (fn *formulaFuncs) SKEW(argsList *list.List) formulaArg {
 		}
 	}
 	if count > 2 {
-		return newNumberFormulaArg(summer * (count / ((count - 1) * (count - 2))))
+		if name == "SKEW" {
+			return newNumberFormulaArg(summer * (count / ((count - 1) * (count - 2))))
+		}
+		return newNumberFormulaArg(summer / count)
 	}
 	return newErrorFormulaArg(formulaErrorDIV, formulaErrorDIV)
 }
 
+// SKEW function calculates the skewness of the distribution of a supplied set
+// of values. The syntax of the function is:
+//
+//    SKEW(number1,[number2],...)
+//
+func (fn *formulaFuncs) SKEW(argsList *list.List) formulaArg {
+	return fn.skew("SKEW", argsList)
+}
+
+// SKEWdotP function calculates the skewness of the distribution of a supplied
+// set of values. The syntax of the function is:
+//
+//    SKEW.P(number1,[number2],...)
+//
+func (fn *formulaFuncs) SKEWdotP(argsList *list.List) formulaArg {
+	return fn.skew("SKEW.P", argsList)
+}
+
+// SLOPE returns the slope of the linear regression line through data points in
+// known_y's and known_x's. The slope is the vertical distance divided by the
+// horizontal distance between any two points on the line, which is the rate
+// of change along the regression line. The syntax of the function is:
+//
+//    SLOPE(known_y's,known_x's)
+//
+func (fn *formulaFuncs) SLOPE(argsList *list.List) formulaArg {
+	return fn.pearsonProduct("SLOPE", argsList)
+}
+
 // SMALL function returns the k'th smallest value from an array of numeric
 // values. The syntax of the function is:
 //
diff --git a/calc_test.go b/calc_test.go
index a7f88b0..6cae4a3 100644
--- a/calc_test.go
+++ b/calc_test.go
@@ -1157,6 +1157,12 @@ func TestCalcCellValue(t *testing.T) {
 		"=SKEW(1,2,3,4,3)": "-0.404796008910937",
 		"=SKEW(A1:B2)":     "0",
 		"=SKEW(A1:D3)":     "0",
+		// SKEW.P
+		"=SKEW.P(1,2,3,4,3)": "-0.27154541788364",
+		"=SKEW.P(A1:B2)":     "0",
+		"=SKEW.P(A1:D3)":     "0",
+		// SLOPE
+		"=SLOPE(A1:A4,B1:B4)": "1",
 		// SMALL
 		"=SMALL(A1:A5,1)": "0",
 		"=SMALL(A1:B5,2)": "1",
@@ -3063,6 +3069,14 @@ func TestCalcCellValue(t *testing.T) {
 		"=SKEW()":     "SKEW requires at least 1 argument",
 		"=SKEW(\"\")": "strconv.ParseFloat: parsing \"\": invalid syntax",
 		"=SKEW(0)":    "#DIV/0!",
+		// SKEW.P
+		"=SKEW.P()":     "SKEW.P requires at least 1 argument",
+		"=SKEW.P(\"\")": "strconv.ParseFloat: parsing \"\": invalid syntax",
+		"=SKEW.P(0)":    "#DIV/0!",
+		// SLOPE
+		"=SLOPE()":            "SLOPE requires 2 arguments",
+		"=SLOPE(A1:A2,B1:B1)": "#N/A",
+		"=SLOPE(A4,A4)":       "#DIV/0!",
 		// SMALL
 		"=SMALL()":           "SMALL requires 2 arguments",
 		"=SMALL(A1:A5,0)":    "k should be > 0",
@@ -4968,6 +4982,89 @@ func TestCalcMODE(t *testing.T) {
 	}
 }
 
+func TestCalcPEARSON(t *testing.T) {
+	cellData := [][]interface{}{
+		{"x", "y"},
+		{1, 10.11},
+		{2, 22.9},
+		{2, 27.61},
+		{3, 27.61},
+		{4, 11.15},
+		{5, 31.08},
+		{6, 37.9},
+		{7, 33.49},
+		{8, 21.05},
+		{9, 27.01},
+		{10, 45.78},
+		{11, 31.32},
+		{12, 50.57},
+		{13, 45.48},
+		{14, 40.94},
+		{15, 53.76},
+		{16, 36.18},
+		{17, 49.77},
+		{18, 55.66},
+		{19, 63.83},
+		{20, 63.6},
+	}
+	f := prepareCalcData(cellData)
+	formulaList := map[string]string{
+		"=PEARSON(A2:A22,B2:B22)": "0.864129542184994",
+	}
+	for formula, expected := range formulaList {
+		assert.NoError(t, f.SetCellFormula("Sheet1", "C1", formula))
+		result, err := f.CalcCellValue("Sheet1", "C1")
+		assert.NoError(t, err, formula)
+		assert.Equal(t, expected, result, formula)
+	}
+}
+
+func TestCalcRSQ(t *testing.T) {
+	cellData := [][]interface{}{
+		{"known_y's", "known_x's"},
+		{2, 22.9},
+		{7, 33.49},
+		{8, 34.5},
+		{3, 27.61},
+		{4, 19.5},
+		{1, 10.11},
+		{6, 37.9},
+		{5, 31.08},
+	}
+	f := prepareCalcData(cellData)
+	formulaList := map[string]string{
+		"=RSQ(A2:A9,B2:B9)": "0.711666290486784",
+	}
+	for formula, expected := range formulaList {
+		assert.NoError(t, f.SetCellFormula("Sheet1", "C1", formula))
+		result, err := f.CalcCellValue("Sheet1", "C1")
+		assert.NoError(t, err, formula)
+		assert.Equal(t, expected, result, formula)
+	}
+}
+
+func TestCalcSLOP(t *testing.T) {
+	cellData := [][]interface{}{
+		{"known_x's", "known_y's"},
+		{1, 3},
+		{2, 7},
+		{3, 17},
+		{4, 20},
+		{5, 20},
+		{6, 27},
+	}
+	f := prepareCalcData(cellData)
+	formulaList := map[string]string{
+		"=SLOPE(A2:A7,B2:B7)": "0.200826446280992",
+	}
+	for formula, expected := range formulaList {
+		assert.NoError(t, f.SetCellFormula("Sheet1", "C1", formula))
+		result, err := f.CalcCellValue("Sheet1", "C1")
+		assert.NoError(t, err, formula)
+		assert.Equal(t, expected, result, formula)
+	}
+}
+
 func TestCalcSHEET(t *testing.T) {
 	f := NewFile()
 	f.NewSheet("Sheet2")
diff --git a/chart.go b/chart.go
index 8f521fa..f740a2b 100644
--- a/chart.go
+++ b/chart.go
@@ -479,16 +479,11 @@ func parseFormatChartSet(formatSet string) (*formatChart, error) {
 		},
 		Format: formatPicture{
 			FPrintsWithSheet: true,
-			FLocksWithSheet:  false,
-			NoChangeAspect:   false,
-			OffsetX:          0,
-			OffsetY:          0,
 			XScale:           1.0,
 			YScale:           1.0,
 		},
 		Legend: formatChartLegend{
-			Position:      "bottom",
-			ShowLegendKey: false,
+			Position: "bottom",
 		},
 		Title: formatChartTitle{
 			Name: " ",
diff --git a/picture.go b/picture.go
index 515f15f..919262c 100644
--- a/picture.go
+++ b/picture.go
@@ -31,11 +31,6 @@ import (
 func parseFormatPictureSet(formatSet string) (*formatPicture, error) {
 	format := formatPicture{
 		FPrintsWithSheet: true,
-		FLocksWithSheet:  false,
-		NoChangeAspect:   false,
-		Autofit:          false,
-		OffsetX:          0,
-		OffsetY:          0,
 		XScale:           1.0,
 		YScale:           1.0,
 	}
diff --git a/shape.go b/shape.go
index 8aefeea..db76867 100644
--- a/shape.go
+++ b/shape.go
@@ -25,15 +25,10 @@ func parseFormatShapeSet(formatSet string) (*formatShape, error) {
 		Height: 160,
 		Format: formatPicture{
 			FPrintsWithSheet: true,
-			FLocksWithSheet:  false,
-			NoChangeAspect:   false,
-			OffsetX:          0,
-			OffsetY:          0,
 			XScale:           1.0,
 			YScale:           1.0,
 		},
-		Line:  formatLine{Width: 1},
-		Macro: "",
+		Line: formatLine{Width: 1},
 	}
 	err := json.Unmarshal([]byte(formatSet), &format)
 	return &format, err
diff --git a/table.go b/table.go
index 0311a8e..b01c1cb 100644
--- a/table.go
+++ b/table.go
@@ -23,10 +23,7 @@ import (
 // parseFormatTableSet provides a function to parse the format settings of the
 // table with default value.
 func parseFormatTableSet(formatSet string) (*formatTable, error) {
-	format := formatTable{
-		TableStyle:     "",
-		ShowRowStripes: true,
-	}
+	format := formatTable{ShowRowStripes: true}
 	err := json.Unmarshal(parseFormatSet(formatSet), &format)
 	return &format, err
 }