Removed spaces from top-level directory names.

Spaces tend to cause annoyances in a Unix-style shell environment.
This change fixes that.

87_3-D_Plot/java/Plot3D.java

@@ -0,0 +1,97 @@
+import java.lang.Math;
+
+/**
+ * Game of 3-D Plot
+ * <p>
+ * Based on the BASIC game of 3-D Plot here
+ * https://github.com/coding-horror/basic-computer-games/blob/main/87%203-D%20Plot/3dplot.bas
+ * <p>
+ * Note:  The idea was to create a version of the 1970's BASIC game in Java, without introducing
+ * new features - no additional text, error checking, etc has been added.
+ * 
+ * Converted from BASIC to Java by Darren Cardenas.
+ */
+ 
+// Java class names cannot begin with a letter, so class name 3dplot cannot be used
+public class Plot3D {    
+
+  
+  public void play() {
+
+    showIntro();
+    startGame();
+
+  }  // End of method play  
+  
+  
+  private void showIntro() {    
+    
+    System.out.println(" ".repeat(31) + "3D PLOT");
+    System.out.println(" ".repeat(14) + "CREATIVE COMPUTING  MORRISTOWN, NEW JERSEY");
+    System.out.println("\n\n\n");
+    
+  }  // End of method showIntro      
+
+
+  private void startGame() {        
+
+    float row = 0;
+    int column = 0;
+    int limit = 0;
+    int plotVal = 0;
+    int root = 0;
+    
+    String lineContent = "";
+    
+    // Begin loop through all rows
+    for (row = -30; row <= 30; row += 1.5) {
+      
+      limit = 0;    
+      
+      root = 5 * (int) Math.floor((Math.sqrt(900 - row * row) / 5));
+      
+      // Begin loop through all columns
+      for (column = root; column >= -root; column += -5) {
+        
+        plotVal = 25 + (int) Math.floor(func(Math.sqrt(row * row + column * column)) - 0.7 * column);
+        
+        if (plotVal > limit) {
+          
+          limit = plotVal;
+          
+          // Add whitespace
+          while (lineContent.length() < (plotVal-1)) {
+            lineContent += " ";
+          } 
+
+          lineContent += "*";       
+          
+        }
+
+      }  // End loop through all columns
+      
+      System.out.println(lineContent);    
+            
+      lineContent = "";
+
+    }  // End loop through all rows
+   
+  }  // End of method startGame
+  
+
+  // Function to be plotted
+  public double func(double inputVal) {
+    
+    return (30 * Math.exp(-inputVal * inputVal / 100));    
+    
+  }
+  
+
+  public static void main(String[] args) {
+    
+    Plot3D plot = new Plot3D();
+    plot.play();
+    
+  }  // End of method main
+
+}  // End of class Plot3D