---
title: "Sales Bar Chart"
id: 57015
type: "computer_media"
slug: "sales-bar-chart"
url: "http://localhost/computer_media/sales-bar-chart/"
markdown_url: "http://localhost/computer_media/sales-bar-chart.md"
published_at: "2024-10-02T07:38:53+00:00"
modified_at: "2026-03-30T21:20:10+00:00"
author: "David Anderson"
featured_image:
  url: "http://localhost/wp-content/uploads/2024/10/39_Sales.png"
excerpt: "A random-data dual-series bar chart using block graphics to show overlapping sales figures for nuts and bolts across five simulated years."
category:
  - name: "Archived Media"
    slug: "archived-media"
    taxonomy: "category"
    url: "http://localhost/category/archived-media/"
post_tag:
  - name: "Downloadable"
    slug: "downloadable"
    taxonomy: "post_tag"
    url: "http://localhost/tag/downloadable/"
  - name: "TS 1000"
    slug: "ts1000"
    taxonomy: "post_tag"
    url: "http://localhost/tag/ts1000/"
model:
  - name: "Timex/Sinclair 1000"
    slug: "ts-1000"
    taxonomy: "model"
    url: "http://localhost/model/ts-1000/"
genre:
  - name: "Business"
    slug: "business"
    taxonomy: "genre"
    url: "http://localhost/type/business/"
media_contents:
  - id: 56732
    title: "Timex Sinclair Public Domain Library Tape 1001"
    type: "computer_media"
    url: "http://localhost/computer_media/timex-sinclair-public-domain-library-tape-1001/"
media_type: "Program"
mediadate: "198x"
images:
  - url: "http://localhost/wp-content/uploads/2024/10/39_Sales.png"
media_type_tags: "Business"
---

# Sales Bar Chart

This program generates a dual-series horizontal bar chart displaying five years of simulated sales figures for two product lines, nuts and bolts. It uses a 5×2 array to store randomly generated sales values (integers in the range 10–20) and renders the chart using block graphics characters to distinguish where both series overlap, where only nuts exceed a threshold, and where only bolts do. The x-axis labels are printed manually across two lines to represent values 0 through 20 in steps of 2. Output uses tab-separated formatting with inverse-video characters in column headers and a manually positioned axis scale.

***

## Program Analysis

### Program Structure

The program is divided into four logical phases, separated by line-number ranges:

1. **Lines 5–10:** Title REM and array declaration.
2. **Lines 100–140:** Data initialisation — fills the 5×2 array `S` with random values.
3. **Lines 200–499:** Output — prints the chart header, iterates over years, draws bars, and prints the x-axis scale.
4. **Lines 500–510:** Save/auto-run block, not part of normal execution.

### Data Generation

The two-dimensional array `S(5,2)` stores values for five years and two product lines (nuts = column 1, bolts = column 2). Each value is generated by `INT(RND*11+10)`, producing integers uniformly distributed in the range 10–20 inclusive. This means every bar will be at least half the maximum chart width, giving a reasonably compact but always-populated chart.

### Bar Rendering Technique

For each year, a loop over `K` from 1 to 20 tests the relationship between the two series values and the current column position, printing one of three block graphic characters per cell:

| Condition | Escape | Glyph | Meaning |
| --- | --- | --- | --- |
| `S(J,1)>=K` AND `S(J,2)>=K` | `\!!` | ▒ | Both nuts and bolts reach this column |
| `S(J,1)>=K` AND `S(J,2)<K` | `\..` | ▄ | Only nuts reach this column |
| `S(J,2)>=K` AND `S(J,1)<K` | `\~~` | Not a standard zmakebas escape | Only bolts reach this column |

The three `IF` statements at lines 320–340 are mutually exclusive by construction (the cases cover all possibilities when `K` is within the range of either value), so no `ELSE` or branching is needed. When neither series reaches column `K`, none of the conditions is true and nothing is printed, which naturally terminates the bar.

### Notable Idioms

- The header at line 200 uses inverse-video characters embedded in string literals (e.g. `%V`, `%E`, etc.) to highlight the column headers “FIVE YEAR SALES FIG.” and “FOR NUTS() AND BOLTS()”.
- Year labels are computed on the fly as `1984+J` (line 305), covering 1985–1989, avoiding a separate lookup array.
- Double `PRINT` statements at lines 360–370 insert blank lines between year rows, giving the chart visual breathing room without cursor manipulation.
- The x-axis scale (lines 400–410) is split across two `PRINT` statements to handle the two-digit label “10” through “20” breaking into a staggered layout — a common manual workaround for fixed-width character grids.

### Anomalies and Observations

- The bar loop runs to `K=20` (line 310), matching the maximum possible value from data generation, so no bar can overflow. However, if a value were exactly 20, the rightmost cell would still be printed correctly.
- The x-axis label at line 400 shows values “0 2 4 6 8 1 1 1 1 1 2” and line 410 continues “0 2 4 6 8 0”, together representing 0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20. Each bar cell is one character wide, so the scale is in units of 1, not 2 — the printed axis labels do not correctly correspond to the bar positions and are purely decorative approximations.
- The `PRINT "YEAR",,` at line 250 uses double comma tab-stops to position the heading, but since bars begin immediately after the year number with a space (line 305), the visual alignment of “YEAR” with the bars may be off by the width of the year field.
- The `STOP` at line 499 prevents execution from falling through to the `SAVE`/`RUN` block, which is a standard technique for embedding auto-save metadata in a program listing without it executing during normal runs.

## Source Code

```
   5 REM %S%A%L%E%S% %C%H%A%R%T
  10 DIM S(5,2)
 100 FOR J=1 TO 5
 110 FOR K=1 TO 2
 120 LET S(J,K)=INT (RND*11+10)
 130 NEXT K
 140 NEXT J
 200 PRINT "FI%VE YEAR SALES FIG.","FOR NUTS()AND BOLTS()",,,
 250 PRINT "YEAR",,
 300 FOR J=1 TO 5
 305 PRINT 1984+J;" ";
 310 FOR K=1 TO 20
 320 IF S(J,1)>=K AND S(J,2)>=K THEN PRINT "\!!";
 330 IF S(J,1)>=K AND S(J,2)<K THEN PRINT "\..";
 340 IF S(J,2)>=K AND S(J,1)<K THEN PRINT "\~~";
 350 NEXT K
 360 PRINT 
 370 PRINT 
 380 NEXT J
 400 PRINT "    0 2 4 6 8 1 1 1 1 1 2"
 410 PRINT "              0 2 4 6 8 0"
 499 STOP 
 500 SAVE "1003%9"
 510 RUN
```