☰ Contents · Computing

Editing charts and graphs

Lessons 26 · 1 lessons · B. Boltayev, A. Azamatov, A. Asqarov, M. Sodiqov, G. Azamatova. Fundamentals of Informatics and Computer Technology, Grade 8. Second edition. “O‘zbekiston milliy ensiklopediyasi” State Scientific Publishing House, Tashkent, 2015
26

Editing charts and graphs

Textbook: pp. 114–119
GoalEdits and formats a finished chart, solves a system of equations with a graph and takes care that the chart is honest.
New words
editing: changing a chart’s type, titles, colours, size or data · tahrirlashcontext menu: the list of actions that opens on right-click of an element · kontekst-menyuaxis scale: the smallest and largest value and the step of an axis · shkalaintersection point: where two graphs meet; it solves the system · kesishish nuqtasi
Explanation

A finished chart can be changed: its type can be switched, and its size, titles, colours, font and background adjusted. To do this select a chart element (axis, legend, title, data series) and open the right-click context menu or the Format panel. The axis format sets the smallest and largest value of the scale and the main step. Editing lets us solve a task graphically: bring two equations to the form y =, plot both functions in one chart, and the point where the lines cross is the solution; we narrow the x interval and the step to locate the point more precisely. A chart must be honest: not starting a column chart’s axis at 0 makes a small difference look big and misleads the reader.

Worked examples
System y = x + 1 and y = –2x + 7. For x = 0, 1, 2, 3, 4: y1 = 1, 2, 3, 4, 5; y2 = 7, 5, 3, 1, –1. The values are equal at x = 2 (3 and 3), so the solution is (2; 3). Check: 2 + 1 = 3 and –2 · 2 + 7 = 3.
Screen time: from Monday to Sunday 90, 80, 70, 60, 120, 150, 130 minutes. We make a column chart, set the vertical axis scale from 0 to 160 with step 20, the title “Weekly screen time” and the axis name “minutes”. The total is 700 minutes, an average of 700 : 7 = 100 minutes a day.
Class activity

“Edit workshop”: the teacher gives a plain chart; groups make it easy to read with a title, axis names, colours and labels.

Practice
1
How can the settings of a chart element be opened?
2
In the system y = x + 3 and y = –x + 9, what is x? (x + 3 = –x + 9)
3
Weekly screen time totals 700 minutes. How many minutes is that per day on average?
4
Why is starting the axis at 5000 misleading in a column chart of 5100, 5200 and 5300?