How to avoid empty space in the inside of the equations

[kanagakumar]

Dear Team,

I need to avoid the empty boundary space around equations inside the frame. I have to exactly fit the equation such that there is no white space. Can you provide or suggest any script related to this request?

Please advise.

Or any option available in the mathtype to fix this issue?

Please see the screenshot for your reference below:

Thanks

kanagakumar

[m1b]

It depends on how the artwork for the equation is structured. But are you able to import them with "Show Import Options" on? And then (depending on the file format—hopefully PDF or similar vector format) try choosing: Art

That can sometimes help in this sort of case. The problem may be that the program that generated the equation artwork file may have included a white box behind it, so Indesign thinks that this is part of the art.

If the above isn't helpful, could you share a couple of samples of the equation artwork?

- Mark

[kanagakumar]

Dear Mark,

Thanks for your reply.

Please see the attachment for the samples mathtype equations.

Thanks

kk

[m1b]

Thanks @kanagakumar that is helpful. The problem in your case appears to be that the bounding box of the artwork is the bounds of the glyphs, which is usually bigger than the actual letterform itself (there is space to either side of the letterform so that there is a pleasing gap between adjacent letterforms). This works badly for your situation though.

A possible solution is to outline the fonts so that they are vector paths rather than font glyphs. Then the bounding box is tight to the edges:

If you think this is a good option, you can see if you can convert to outlines in the exporting stage (from your maths typesetting app) or you can convert the .eps files to outline using Illustrator. Let me know if you need help doing the converting as it may be possible to script it (eg. if there are hundreds of files).

- Mark.

[kanagakumar]

Dear Mark,

Thanks for your suggestion.

The client is not permitted to convert other types (such as outline format or.ai) for any additional options.

Client need original mathtype equation format (.eps).

Thanks

kk

[m1b]

Oh dear, that is quite strange.

Do you know the reason why the must have these exact .eps files? It is very unlikely that editability is the issue because .eps is very unlikely to be the native file format for these equations—they are more likely to have been exported as eps from the native format). Anyway you can still keep the non-outlined versions for editing.

But since you are not permitted to outline them then we must work with what we have. Perhaps manually adjusting? Sorry. Hopefully an expert will have a good idea soon. We must wait.

- Mark

[brian_p_dts]

Can you adjust the crop settings on the placed graphic in an object style consistently?

[rob day]

Hi @kanagakumar , the background of the eps is [None], and the eps container can also be [None], can you describe a case where the size of the bounding box is a problem? The parent container could be made smaller via scripting, but it would not change the text’s output.

[Joel Cherney]

I was actually in a long thread about this very issue a few months back, and after many, many attempts to figure out how to get something out of MathType that wouldn't be padded in this way, it was pointed out that @MrMathType — Retired himself had already posted a padding-reduction solution. You might try one of the many other options suggested there. 

[rob day]

Hi Joel, What is the problem with the bounds if the object fill is transparent — [None]? Is it about matching the baselines? If the bottom padding is consistent, a baseline shift could be applied to the anchor.

[Joel Cherney]

I hadn't noticed your reply when I wrote mine - and I like the direction you're thinking in, Rob. I assume that you could safely reduce the size of the bounding box on all four sides. When I placed the provided sample EPS files as inline anchored objects, I found that I could reduce the bounding box in size by around, but not exactly, two points on each side. When I did so, the baseline of the text in the EPS sat exactly where you'd expect if you were working with live text, without baseline adjustment. 

[rob day]

If the issue really is base line alignment, then I think trying to ajust the bounds would not work because setting the bottom bound to the baseline would cut off parts of the characters that fall below the baseline:

Setting the baseline shift of the anchored object would not cut off the glyphs, but I don’t think the needed amount would be consistent:

[Peter Kahrel]

MathType (EPS) equations always have 1 point padding. In the post that Joel cited Mr MathType says 2 points, but in my experience it's always 1, but that may be because I usually dealt with MT EPSs that didn't come from Word.

Anyway, you can't just chop off 1 or 2 points because the padding doesn't take into account font metrics (undershoot, overshoot, left and right side bearings) so whatever fixed padding value you use, you always get it wrong. There's just no good way to clip MT EPSs to their content.

The second problem mentioned, how to align the EPSs baseline with the parent line's baseline, can be handled accurately. The EPS file contains some metrics. Look for the line that starts with %%Baseline:

%%Baseline: 14

This equations's baseline is 14 points. You can then use the method outlined by Rob (setting wrap and baseline adjustment) to align the equation's baseline.

[rob day]

Hi Peter, Thanks! Not sure if aligning the baselines is what @kanagakumar is after, but it does indeed work— the negative value of the %%Baseline number aligns the baselines. Is there a way to read the contents of an EPS text via scripting? Calling file.open("r")  doesn’t seem to work for me:

[Peter Kahrel]

Maybe you should set the encoding to binary. This code works for me (on Windows):

f = File ('d:/test/sample.eps');
f.encoding = 'BINARY';
f.open('r');
s = f.read();
f.close();

alert ('Baseline: ' + s.match (/%%Baseline:\s(\d+)/)[1]);

[rob day]

That worked thanks

[m1b]

You can also start reading after the binary bytes (the text starts around byte 35 or so):

f.open('r');
f.seek(100);
var baseline = Number((f.read(300)).match(/Baseline:\s([\d\/]+)/)[1]);
f.close();

At least this worked for me.

- Mark

[Peter Kahrel]

> You can also start reading after the binary bytes (the text starts around byte 35 or so):

That's tricky, because before the line with Baseline you have variable-length items such as the file name and font names.

[m1b]

Yeah and since I have no idea what is encoded before byte 35, for all I know it could be variable too! I retract my suggestion. 🙂

- Mark

[kanagakumar]

Dear Team,

Still, I am working manually for all equation frames. 

Thanks

kk

[Peter Kahrel]

The discussion above suggests that unfortunately there isn't an automated solution to deal with the empty space.

[rob day]

working manually for all equation frames.

Hi @kanagakumar , Why do the bounds matter? The eps files have no background and their container frame can be filled with [None], so changing the bounds of the container frame or the eps would not affect output. You would still need to manually align the eps to the baseline, if that’s the issue.

[kanagakumar]

Dear Team,

Sure, I will continue working manually.

Kindly let me know if you have any scripts that meet my needs or if you have any other alternatives.

Thank you for taking the time to respond to my inquiry. I'm going to close our conversation as of now.

@Peter Kahrel @rob day @m1b @Joel Cherney @brian_p_dts 

Thank you for your support and guidance.

Thanks

kk

[m1b · Accepted solution]

Hi @kanagakumar and others, really you guys have worked out the hard parts already. So I've written a script that uses your insights, and hopefully this will do what you want.

I have assumed that the equations are all eps graphics that are anchored in text. I've included options to set a uniform scale for the equations, and also to fit the frame to the content—this is critical, otherwise the baseline might not be correct.

Give it a try and let me know how you go.

- Mark

Example, using scalePercent: 120:

/**
 * Aligns all anchored EPS math equation graphics to their baseline
 * by using the `Baseline` value in the eps markup.
 *
 * Options:
 *   - apply an object style to each equation's frame
 *   - apply a separate object style for "display" equation's frames
 *   - scale the equation graphic
 *   - fit content to frame (NOTE: turning this off may result in baseline misalignments.)
 *   - adjusts equations cropping on left and right sides.
 *
 * Notes:
 *   - "Display" equations start a line, are displayed on the line by themselves
 *      and do not have baseline adjustments.
 * @author m1b
 * @discussion https://community.adobe.com/t5/indesign-discussions/how-to-avoid-empty-space-in-the-inside-of-the-equations/m-p/14460828
 */
function main() {

    var settings = {
        equationInlineStyleName: 'Equation Inline',
        equationDisplayStyleName: 'EQ-text Wrap',
        scalePercent: 100,
        leftSideBearing: -1,
        rightSidebearing: -1,
        fitFrameToContent: true,
    };

    app.scriptPreferences.measurementUnit = MeasurementUnits.POINTS;

    var counter = 0,
        doc = app.activeDocument,
        inlineEquationStyle = getThing(doc.allObjectStyles, 'name', settings.equationInlineStyleName),
        displayEquationStyle = getThing(doc.allObjectStyles, 'name', settings.equationDisplayStyleName),
        graphics = doc.allGraphics;

    for (var i = 0, eps, baseline, newYOffset, isDisplay; i < graphics.length; i++) {

        if (
            'EPS' !== graphics[i].constructor.name
            || undefined == graphics[i].parent.anchoredObjectSettings
        )
            // ignore non-eps and non-anchored graphics
            continue;

        eps = graphics[i];

        // get the baseline from the eps file
        baseline = getBaselineOfEPS(eps);

        if (undefined == baseline)
            // didn't get baseline
            continue;

        // "display" equations are handled differently
        isDisplay = true === isDisplayEquation(eps);

        // apply object style
        if (isDisplay && displayEquationStyle)
            eps.parent.appliedObjectStyle = displayEquationStyle;

        else if (inlineEquationStyle)
            eps.parent.appliedObjectStyle = inlineEquationStyle;

        // scale
        if (settings.scalePercent)
            eps.properties = {
                verticalScale: settings.scalePercent,
                horizontalScale: settings.scalePercent,
            };

        // adjust the frame
        crop(eps, [0, settings.leftSideBearing, 0, settings.rightSidebearing], settings.fitFrameToContent);

        // the anchored object Y offset value
        newYOffset = -baseline * (eps.verticalScale / 100);

        if (!isDisplay)
            // adjust the anchored position
            eps.parent.anchoredObjectSettings.anchorYoffset = newYOffset;

        counter++;

    }

    alert('Adjusted ' + counter + ' anchored eps graphics.');

};
app.doScript(main, ScriptLanguage.JAVASCRIPT, undefined, UndoModes.ENTIRE_SCRIPT, 'Align Anchored Equations');

/**
 * Returns the `baseline` value
 * from the EPS file.
 * @author Peter Kahrel
 * @author Rob Day
 * @author m1b
 * @version 2024-03-09
 * @param {EPS} graphic - an EPS graphic.
 * @returns {Number} - the baseline extracted from the file.
 */
function getBaselineOfEPS(graphic) {

    var f = File(graphic.itemLink.filePath);

    if (!f.exists)
        return;

    f.encoding = 'BINARY';
    f.open('r');
    var str = f.read();
    f.close();

    return Number(str.match(/%%Baseline:\s(\d+)/)[1] || 0);

};

/**
 * Returns a thing with matching property.
 * @param {Array|collection} things - the things to look through, eg. PageItems.
 * @param {String} key - the property name, eg. 'name'.
 * @param {*} value - the value to match.
 * @returns {*} - the thing.
 */
function getThing(things, key, value) {

    for (var i = 0; i < things.length; i++)
        if (things[i][key] == value)
            return things[i];

};

/**
 * Adjust a graphic's container's bounds,
 * either relative to the graphic, or
 * relative to the graphic's container.
 *
 * Example:
 *   crop(myGraphic,[0,0,0,0]); // equivalent to fit frame to content
 *
 * Example:
 *   copy(mygraphic, [-1,-1,-1,-1], false); // reduce frame by 1 point all around
 *
 * @author m1b
 * @version 2024-03-12
 * @param {contained object} graphic - the target graphic, eg. PDF.
 * @param {Array<Number>} offset - the adjustment to make, in points, in current units to [top, left, bottom, right].
 * @param {Boolean} adjustRelativeToGraphic - whether the adjustment is relative to graphic object; otherwise will be relative to graphic's parentframe (default: true).
 */
function crop(graphic, offset, adjustRelativeToGraphic) {

    var frame = graphic.parent,
        bounds = false !== adjustRelativeToGraphic
            ? graphic.geometricBounds
            : frame.geometricBounds;

    if (undefined == bounds)
        return;

    frame.geometricBounds = [
        bounds[0] - offset[0],
        bounds[1] - offset[1],
        bounds[2] + offset[2],
        bounds[3] + offset[3],
    ];

};

/**
 * Returns true when the supplied EPS
 * is a "Display" equation.
 * @param {EPS} eps - an Indesign EPS graphic.
 * @returns {Boolean}
 */
function isDisplayEquation(eps) {

    return {
        'EQ': true,
        'EQ-I': true,
    }[eps.parent.parent.appliedParagraphStyle.name];

};

Edit 2024-03-12: Added the crop function and added "sidebearings" to the settings object so that the equation graphic's frames can be adjusted on the left and right.

Edit 2024-03-12: Added handling of "display" equations as per OP's comments.

Edit 2024-03-12: Changed isDisplayEquation function as per OP's comments.

[Robert at ID-Tasker]

Hi @kanagakumar and others, really you guys have worked out the hard parts already. So I've written a script that uses your insights, and hopefully this will do what you want.

By @m1b

There are a lot of scripts to POSITION equations - and all of them rather modify BaselineShift of the Parent Character instead of AnchoredObjectSettings - but the whole discussion is about - and what OP really wants - is to CROP equations - remove extra space around the equation so there is no white margin - I don't think your script is doing that, right?