LibreOffice – exporting high-resolution TIFF/TIF files

Posted on by rcragun

As a scholar who regularly publishes work with charts and graphs, I’m often confronted with varied requirements from publishers for the format in which they want the charts and graphs. Most often, the format is as a TIFF/TIF file, typically with at least 300 dpi and somewhere around 1500×1500 pixels. I make most of my charts in LibreOffice Calc, though occasionally I make some in R as well.

I have recently been editing several volumes in which I had to manage the charts and graphs of other scholars as well. As the editor, I had to make sure the final images met the criteria detailed above. Since scholars often make charts and graphs in Word, it took a little finagling to come up with a quick and easy way to export the images in the format needed by the publisher. Since I did finally figure this out, I figured I’d post it here so I remember how to do this in the future. Luckily, LibreOffice works extremely well with these formats (for the most part), which makes this quite easy.

LibreOffice Calc

Assuming you have created your chart/graph in LibreOffice Calc, exporting it into a TIF format should be fairly easy, though it requires an unfortunate extra step. Here’s a chart I created in LibreOffice Calc:

The LibreOffice programmers make it so you can just right-click on the graph and select “Export as Image.”

When you do this, you’ll get this pop-up window asking where you want to save the image and, more importantly, the format:

Here’s where you get a problem. If you select TIFF, you’ll get a .tif file, but the resolution will be basically the same as what you see on your screen, like this:

Ideally, LibreOffice would ask you what DPI and resolution you want once you select the TIFF format and would then export the chart in that resolution and you’d be done in one simple step. Alas, that’s not an option when you export from LibreOffice Calc.

What you can do instead is copy your chart, open an empty LibreOffice Writer document, and paste it into the document, like this:

Then, go up to File -> Export, like this:

You’ll get the same prompt as before asking what you want to name the file and format. Name the file and select PNG format then click “Save.” What you’re looking for is the window that pops up next:

In this window, you can change the DPI to 300 (do this first) and then change the width and height (they are typically linked, so, if you change one, the other automatically changes). When you’re done, click “OK.” The file you’ll get will be 300 DPI and whatever pixels you chose:

Now, open that file with any image editing software (I’m using Gwenview on KDE for this example) and simply select File->Save As:

Now select the TIFF format. Once you save it, you’ll have a TIFF file with the proper DPI and resolution per the publisher’s instructions. The resulting TIFF file will be huge, but it will meet the criteria of the publisher:

NOTE:

The other way to do this is to copy your chart into a LibreOffice Draw file that has been modified with a huge area (e.g., 4000×4000 pixels). You can then expand your chart to file the area in the LibreOffice Draw document and then export the image. However, depending on the original format of your chart/graph, you may have to resize the text if you do this, which is a pain. However, this will give you a much larger image file. But the approach above is much easier.

The tutorial above used LibreOffice 6.4.4.2.

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LibreOffice Calc: Graphs with Two y-axes with Different Scales

Posted on by rcragun

While a bit technical, it’s occasionally useful to plot multiple data series that have very different scales in the same chart. Let me give an example to illustrate. Let’s say I want to see whether the number of Mormon temples being built aligns with the number of Mormon stakes (akin to a Catholic diocese) that are organized over time. (I’m a sociologist who studies religion; you’ll just have to go with my examples.)

However, the number of Mormon temples is in the hundreds while the number of Mormon stakes is in the thousands. If I plot them both on the same chart with the same y-axis (that’s the vertical axis), the number of Mormon temples is going to look really small and I won’t be able to see the variation over time in the number of temples, like this:

The chart shows that stakes have increased, but it looks like the number of temples has barely moved. LibreOffice Calc automatically creates the scale used for the y-axis based on the scale of the larger of the two data series, in this case, the number of stakes. Thus, the maximum value is 4,000 and the minimum is 0. What I want to do in this tutorial is to illustrate how to add a second y-axis on the right side of the chart that uses a different scale that is more appropriate for the number of temples.

To begin with, go ahead and create your chart with at least two data series, as I have shown in other tutorials, like this one. Once you have your chart with two data series complete, now it’s time to add a second y-axis with a different scale.

First, click on your chart then double-click it to open chart editing. Then, select the chart area by clicking on one of the axes (left or right doesn’t matter) and then right-click it. You’ll get a context menu with the option “Insert/Delete axes…” Select that:

In the window that pops up, you’ll see a second column labeled “Secondary Axes.” You want to select “Y axis.”

Click “OK” and you’ll see that a second y-axis has been added to your chart on the right side using the same metric as the left side:

The next steps are pretty straightforward, but before you do them, you should pause and think for a second so you don’t have to go back and undo what you’re about to do. You’re going to change the scale of one of the two y-axes, but which axis do you want to change? There isn’t a right or wrong answer here. Generally speaking, I typically see charts like this with the smaller of the two ranges assigned to the left axis and the larger assigned to the right axis, but, again, it is entirely up to you which way you choose to go. At this point, though, you need to make a decision. Then you can move to the next step.

I’m going to follow my suggestion above and change the y-axis on the left to a scale that fits with the number of temples (so, a smaller range of values) and keep the y-axis on the right with the larger range for the number of stakes. But before I change the scales of the axes, I need to tell LibreOffice which data series is going to align with which axis. Here’s how. Click on one of your data series lines, then right-click it and select “Format Data Series.”

In the window that pops up, you’ll see on the “Options” tab right at the top an option that says, “Align Data Series to” and then “Primary Y axis” (this is the one on the left of the chart) or “Secondary Y axis” (this is the one on the right of the chart). Since I selected the number of temples first, I’m going to leave that one aligned to the Primary Y axis:

Hit OK. Then select the other line (in my case, the number of stakes), right-click it, and select “Format Data Series.” On the “Options” tab, I’m going to select to align this line with the “Secondary Y axis”:

Once you do that, you’ll see that LibreOffice automatically adjusts the scale of the other axis. Here’s how my chart now looks:

You can see that it changed the scale of the Primary Y-axis (the one on the left) to a maximum of 250 to reflect the smaller range of that data series. If you want to customize the scale used, you can always click on the axis you want to modify and then right-click it and select “Format Axis”:

In the window that pops up, you can modify the scale of the axis by clicking on the “Scale” tab. If you want to change the values, click on the box next to “Automatic” to unselect it so you can put in your own values, then customize the value you add, like this:

When you have modified the scale to your satisfaction, select “OK” and your graph will be updated with the scale you want, like this:

The resulting chart now has two axes with different scales. It would be a good idea at this point to label the axes to reflect the differences. Simply right-click on the chart and select “Insert Titles.” In that window, add appropriate titles. The left y-axis is simply the Axes while the right y-axis is considered the “Secondary Axes”:

And your final graph will look something like this:

That’s how you can create a chart with two axes in LibreOffice Calc.

NOTE: This example was done in LibreOffice Calc version: 6.4.2.2 on a Linux-based operating system (Kubuntu 19.10).

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LibreOffice Calc: Interpolating Missing Values in Graphs

Posted on by rcragun

Here’s my situation. I have some data over time but I’m missing values in specific years. I want to graph that data but would rather not have to estimate all of the missing values. It turns out, LibreOffice Calc can do that for you in your chart. Here’s how…

Imagine I’m plotting the number of congregations in the LDS Church over time (weird example, I’m sure you’re thinking, but I’m a sociologist who studies religion, so, yeah, that’s what I do). I have the number of congregations in 1841, 1849, 1901, etc. Basically, I have the number in certain years, but I’m missing the number of congregations in lots of other years. I could interpolate the missing values (Excel has this function built in; LibreOffice Calc does not, but you can do it following the approach I have detailed here). But, I don’t really need to do that for my project. I just need a chart that shows the growth of congregations over time.

My data are organized into two columns. Column A is years and ranges from 1841 through 2019. Column B is the number of congregations with the values I have and lots of blank cells:

Select the cells you want to plot (A1:B176 in my case) then click on “Insert Chart”:

You’ll get this window:

Since I want a Line chart, I’m going to select “Line” and because I want “points and lines,” I’m going to select that option as well. I also want “Smooth” lines rather than “Straight” lines, so I select that option, too:

Click “Next >” at the bottom. Since you already selected your Data range, you shouldn’t have to change that. However, we do want the “First column as label” for the x-axis of the chart. So, select that option:

Then select “Next >”. You shouldn’t have to change anything on the Data Series tab, so you can hit “Next >” again. On the Chart Elements tab, you’ll want to describe your chart elements. Add a Title and label your x-axis and y-axis. I also didn’t need a legend since I’m only plotting one data series, so I turned that off:

Then click “Finish.” You’ll have a chart, but it only has the points for the years when you have data, like this:

To add a line connecting the points and interpolating the missing data, click on the chart, then double-click it to modify the chart. Once you’re inside the chart, click on one of the points to select the data series, then right-click and select “Format data series”:

On the “Options” tab you’ll see “Plot Options” and just below that, “Plot missing values.” The default is “Leave gap.” Select “Continue line” and it will interpolate the missing values for you:

Select “Ok” and your line chart will now actually have a line, like this:

There you have it. A line chart with interpolated missing values in LibreOffice Calc without you having to calculate all of the missing values.

NOTE: This example was done in LibreOffice Calc version: 6.4.2.2 on a Linux-based operating system (Kubuntu 19.10).

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