# SGN: Your Sign Language Interpreter

Ever need your Commodore 64 to tell you whether a number is positive, negative, or zero? Look no further than the `SGN`

command, your sign language interpreter! This simple yet powerful function takes any numeric value and reveals its sign, returning -1 for negative numbers, 0 for zero, and 1 for positive numbers. Think of it as your mathematical compass, always pointing you in the right direction!

### Syntax

```
SGN(<number>)
```

Where:
- `<number>`

: The numeric value whose sign you want to determine. Can be any valid numeric expression.

### Applications

The `SGN`

function is surprisingly useful for:

**Conditional logic:**Make decisions based on whether a value is positive, negative, or zero.**Sorting:**Use the sign of values to arrange numbers in ascending or descending order.**Mathematical calculations:**Simplify expressions involving absolute values or comparisons.**Game programming:**Determine the direction of movement or change based on sign.

### Code Examples

**1. Basic Sign Determination:**

```
10 X = -5
20 S = SGN(X) :rem S stores the sign of X
30 PRINT S :rem Output: -1
40 Y = 0
50 S = SGN(Y)
60 PRINT S :rem Output: 0
70 Z = 123
80 S = SGN(Z)
90 PRINT S :rem Output: 1
```

This example demonstrates how `SGN`

returns -1 for negative, 0 for zero, and 1 for positive numbers.

**2. Conditional Logic:**

```
10 INPUT "Enter a number: "; N
20 IF SGN(N) = -1 THEN PRINT "Negative"
30 IF SGN(N) = 0 THEN PRINT "Zero"
40 IF SGN(N) = 1 THEN PRINT "Positive"
```

This snippet determines if the user's input is negative, zero, or positive using `SGN`

.

### SGN in the Wild: The Stock Market Tracker

Imagine you're writing a program to track stock prices. The `SGN`

command could help you quickly identify whether a stock's price has increased (positive), decreased (negative), or remained unchanged (zero) compared to the previous day.

Don't get lost in a sea of numbers! With `SGN`

, you can always determine the direction a number is pointing, whether it's up, down, or staying put. It's a simple yet powerful function that can enhance your Commodore 64 programming skills and add a touch of mathematical clarity to your code. So embrace the guidance of `SGN`

and let it lead you to positive results!