Simplify projection table generation.

Instead of pre-allocating the grid and using tricky indexing to fill in
the cells, just fully regenerate it. But do it columnwise first, and
then transpose it.

moon/moon.go

@@ -2,6 +2,7 @@ package moon
 
 import (
 	"context"
+	"fmt"
 	"math"
 	"time"
 
@@ -14,6 +15,7 @@ type Math struct {
 	CurrentPrice coindesk.Price
 	Columns      []Column
 	Goals        []Goal
+	Labels       []string
 }
 
 func NewMath(asset coindesk.Asset, goals []Goal, bases []Base) (m Math) {
@@ -22,10 +24,14 @@ func NewMath(asset coindesk.Asset, goals []Goal, bases []Base) (m Math) {
 	}
 	m.Asset = asset
 	m.Goals = goals
+	m.Labels = []string{"Starting", "CDPR"}
 	m.Columns = make([]Column, len(bases))
 	for i := range bases {
 		m.Columns[i].Base = bases[i]
 	}
+	for i := range goals {
+		m.Labels = append(m.Labels, goals[i].Name)
+	}
 	return
 }
 
@@ -106,6 +112,25 @@ type Column struct {
 	Projections   Projection
 }
 
+func (c *Column) Column() (entries []string) {
+	entries = append(entries, fmt.Sprintf("$%.2f", c.StartingPrice))
+	entries = append(entries, fmt.Sprintf("%.2f%%", (c.CDPR-1)*100))
+	never := c.CDPR <= 1
+	for i := range c.Projections.Dates {
+		var cell string
+		if never {
+			cell = "NEVER!!!!!"
+		} else {
+			cell = c.
+				Projections.
+				Dates[i].
+				Format("2006-01-02")
+		}
+		entries = append(entries, cell)
+	}
+	return
+}
+
 var DefaultGoals = []Goal{
 	{"$100k", 100000},
 	{"$150k", 150000},