[Solved] How to make a simple line graph

[Chrysanthemum]

I am in General Chemistry I, and our instructor has us make line graphs occasionally. He told us he prefers them made in Excel, since they look cleaner and are easier to read. I have tried, but I cannot understand the direction for creating a graph/chart in Open Office. When it asks me for my data range, the examples are in some sort of computer-speak language that makes no sense to me, so I have no idea how to apply it to my graph.

Basically, I have to make a graph with milliliters on the y-axis in ranges between 100 and 400 ml. and temperatures in Celsius on the x-axis with a range from -400 to 100 degrees. We have to plot 4 points ( mine where 95* C at 260ml,and 7*C at 214.5 ml)(And 99* C at 276ml and 7*C at 210.3ml) and have lines drawn through them to extrapolate the temperature they would be at zero volume in ml, aka absolute zero. Any help in learning how to set up these types of graphs would be appreciated.

[Hagar Delest]

Have you checked the online guide? There is a direct link at the top of the Calc forum (where I've moved your topic). This is a rather basic task so better learn by yourself. Perhaps you can upload a sample file to show how are your data (see: How to attach a document here).

[Cambirder]

With your 2 sets of numerical data you need to plot an x y scatter graph not a line graph.

[Chrysanthemum]

I'm reading the wiki, but it's still like reading french.

The example in the Guide is for a very simple chart involving only 12 degrees (months in this case). I can see how easy it would be to enter that data. But I need to be able to make a scale with 500 degrees (Celsius in my case). I started entering every degree one at at time, starting with -400, -399, -398, etc, and I realized there must be a faster way to doing this. Isn't there?

[Robert Tucker]

Can you not use the TREND function to find the equation for the straight line then find values for the intercept (note there is also an INTERCEPT function) and the coordinates for the line at the temperature extremes?

Looks as if if you want to be able to extend lines beyond co-ordinates given, Issue 5085 is the issue to vote for.

See also:

http://wiki.services.openoffice.org/wik ... rend_lines

[Cambirder]

I can see how easy it would be to enter that data. But I need to be able to make a scale with 500 degrees

All you need to do is plot your 4 points to create the basic graph, and once you have done that you need to edit the scale on the x-axis. Set minimum to -400 and maximum to 100. All that remains is to add a trend line.

[Zizi64]

Basically, I have to make a graph with milliliters on the y-axis in ranges between 100 and 400 ml. and temperatures in Celsius on the x-axis with a range from -400 to 100 degrees.

0 Kelvin = -273,15 °C -> there is nothing to be "colder" in the Universe. Why want you make a graph with -400 °C?

Here is an example graph in the attached file. You can examine the graph type (scatter type) and the Data Range and Data Series (the reference of cell range, containing the x and y values)

Scatter graph.ods

(22.16 KiB) Downloaded 845 times

(Each graph /line/ have different cellrange for "x" values.
You can see the inserted (linear) trendlines and the equations of trendlines.
The example graph have two "y" axis in user defined position, and x/y gridlines.

...just click(/double click/right mouseclick) on graph elements (axes, trendlines, etc.)

[Chrysanthemum]

0 Kelvin = -273,15 °C -> there is nothing to be "colder" in the Universe. Why want you make a graph with -400 °C?

Thanks for the help! Actually your graph shows exactly why I needed to be able to graph out to -400. One trial produced nearly perfect results. The other was wildly off. But both results had to be on the graph even if one was obviously impossible. It just shows that a mistake was made somewhere in the experiment. Using our graph we are to calculate our percentage error.