查看“︁LibreOffice 3.4入门/Math入门”︁的源代码

== '''數學'''是什麼？ ==
'''數學'''是LibreOffice裏頭用於繕打數學式子的元件。'''數學'''通常用於編輯文件中的數學式，不過也可在其他元件中引用'''數學'''的功能，或是單獨地使用。在Writer下引用'''數學'''功能時，所生成的方程式是Writer的一個物件。



{| style="border-spacing:0;"
| style="background-color:#94bd5e;border-top:1pt solid #999999;border-bottom:1pt solid #999999;border-left:none;border-right:none;padding:0.15cm;"| <center>'''注意'''</center>
| style="border-top:1pt solid #999999;border-bottom:1pt solid #999999;border-left:none;border-right:none;padding:0.15cm;"| 方程式編輯器用於繕打含符號的方程式，而非用於計算或是數值求解。若您想要進行計算或是數值求解，請參閱''Calc入門''。

|}

{| style="border-spacing:0;"
! <center><math>\frac{\mathit{df}\left(x\right)}{\mathit{dx}}=\ln \left(x\right)+{\tan }^{-1}\left({x}^{2}\right)</math> </center>
! (1)

|-

|}
=== 讓我們開始吧 ===
如果您想要輸入一條方程式，請依序點選'''插入 > 物件 > 公式'''.

方程式編輯器開啟後會在螢幕的下方出現，同時可能還會跑出個帶有基本構件按鈕的懸浮視窗。您也會在文件輸入區中見到一個帶灰邊的小框，其中會顯示出您所輸入的方程式，請見圖246.


<center></center>

== Entering a formula ==
The equation editor uses a markup language to represent formulas. For example, ''%beta'' creates the Greek character beta (<math>\beta </math>). This markup is designed to read in a similar way to English whenever possible. For example, ''a over b'' produces a fraction: <math>\frac{a}{b}</math>.

You can enter a formula in three ways:

* Select a symbol from the Elements window.
* Right-click on the equation editor and select the symbol from the context menu.
* Type markup in the equation editor.

The context menu and the Elements window insert the markup corresponding to a symbol. This provides a convenient way to learn the LibreOffice Math markup.


{| style="border-spacing:0;"
| style="background-color:#94bd5e;border-top:1pt solid #999999;border-bottom:1pt solid #999999;border-left:none;border-right:none;padding:0.15cm;"| <center>'''Note'''</center>
| style="background-color:transparent;border-top:1pt solid #999999;border-bottom:1pt solid #999999;border-left:none;border-right:none;padding:0.15cm;"| Click on the document body to exit the formula editor.

Double-click on a formula to enter the formula editor again.

|}
=== The Elements window ===
The simplest method for entering a formula is the Elements window.

<center>[[Image:|thumb|''Figure 247: Symbols are divided into categories'']] </center>

The Elements window is divided into two main parts.

* The '''top''' shows the symbol categories. Click on these to change the list of symbols.
* The '''bottom''' shows the symbols available in the current category.


{| style="border-spacing:0;"
| style="background-color:#83caff;border-top:1pt solid #999999;border-bottom:1pt solid #999999;border-left:none;border-right:none;padding:0.15cm;"| <center>'''Tip'''</center>
| style="background-color:transparent;border-top:1pt solid #999999;border-bottom:1pt solid #999999;border-left:none;border-right:none;padding:0.15cm;"| You can hide or show the Elements window with '''View > Elements'''.

|}
==== Example 1:<math>5\times 4</math> ====
For this example we will enter a simple formula:<math>5\times 4</math>. On the Elements window:

# Select the top-left button of the categories (top) section.
# Click on the multiplication symbol.

<center>[[Image:|thumb|''Figure 248: Selecting the multiplication symbol'']] </center>

When you select the multiplication symbol on the Elements window, two things happen:

* The equation editor shows the markup:<math>\text{? times ?}</math>
* The body of the document shows a gray box like this:<math>❑\times ❑</math>

<center>[[Image:|thumb|''Figure 249: Result of selecting the multiplication symbol'']] </center>

<nowiki>The <?> symbols shown in </nowiki>Figure 249 are placeholders that you can replace by other text, for example '''5''' and '''4'''. The equation will update automatically, and the result should resemble Figure 250.


{| style="border-spacing:0;"
| style="background-color:#83caff;border-top:1pt solid #999999;border-bottom:1pt solid #999999;border-left:none;border-right:none;padding:0.15cm;"| <center>'''Tip'''</center>
| style="background-color:transparent;border-top:1pt solid #999999;border-bottom:1pt solid #999999;border-left:none;border-right:none;padding:0.15cm;"| To keep the equation from updating automatically, select '''View >AutoUpdate display'''. To update a formula manually, press ''F9'' or select '''View > Update'''.

|}
<center>[[Image:|thumb|''Figure 250: Result of entering 5 and 4 next to the times operator'']]</center>

=== Right-click (context) menu ===
Another way to access mathematical symbols is to right-click on the equation editor. This pops up the menu shown in Figure 251. The items in this menu correspond exactly to those in the Elements window.

<center>[[Image:|thumb|''Figure 251: Right-click (context) menu'']]</center>

=== Markup ===
You can type the markup directly in the equation editor. For example, you can type '''5 times 4''' to obtain <math>5\times 4</math>. If you know the markup, this can be the fastest way to enter a formula.


{| style="border-spacing:0;"
| style="background-color:#83caff;border-top:1pt solid #999999;border-bottom:1pt solid #999999;border-left:none;border-right:none;padding:0.15cm;"| <center>'''Tip'''</center>
| style="background-color:transparent;border-top:1pt solid #999999;border-bottom:1pt solid #999999;border-left:none;border-right:none;padding:0.15cm;"| The formula markup resembles the way the formula reads in English.

|}
Below is a short list of common equations and their corresponding markup.


{| style="border-spacing:0;"
! Display
! Command
! Display
! Command

|-
| style="background-color:transparent;border-top:none;border-bottom:none;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| <math>a=b</math>
| style="background-color:transparent;border-top:none;border-bottom:none;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| a = b
| style="background-color:transparent;border-top:none;border-bottom:none;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| <math>\sqrt{a}</math>
| style="background-color:transparent;border-top:none;border-bottom:none;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| sqrt {a}

|-
| style="background-color:transparent;border-top:none;border-bottom:none;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| <math>{a}^{2}</math>
| style="background-color:transparent;border-top:none;border-bottom:none;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| a^2
| style="background-color:transparent;border-top:none;border-bottom:none;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| <math>{a}_{n}</math>
| style="background-color:transparent;border-top:none;border-bottom:none;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| a_n

|-
| style="background-color:transparent;border-top:none;border-bottom:none;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| <math>\int f\left(x\right)\mathit{dx}</math>
| style="background-color:transparent;border-top:none;border-bottom:none;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| int f(x) dx
| style="background-color:transparent;border-top:none;border-bottom:none;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| <math>\sum {a}_{n}</math>
| style="background-color:transparent;border-top:none;border-bottom:none;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| sum a_n

|-
| style="background-color:transparent;border-top:none;border-bottom:none;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| <math>a\le b</math>
| style="background-color:transparent;border-top:none;border-bottom:none;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| <nowiki>a <= b</nowiki>
| style="background-color:transparent;border-top:none;border-bottom:none;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| <math>\infty </math>
| style="background-color:transparent;border-top:none;border-bottom:none;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| infinity

|-
| style="background-color:transparent;border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| <math>a\times b</math>
| style="background-color:transparent;border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| a times b
| style="background-color:transparent;border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| <math>x\cdot y</math>
| style="background-color:transparent;border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| x cdot y

|}
=== Greek characters ===
Greek characters (<math>\alpha ,\beta ,\gamma ,\theta </math>, etc) are common in mathematical formulas. ''These characters are not available in the Elements window or the right-click menu''. Fortunately, the markup for Greek characters is simple: Type a % sign followed by the name of the character, in English.

* To write a ''lowercase'' character, type the name of the character in lowercase.
* To write an ''uppercase'' character, type the name of the character in uppercase.

A complete table of Greek characters is provided in the ''Math Guide''. See the table below for some examples.


{| style="border-spacing:0;"
! Lowercase
! Uppercase

|-
| style="background-color:transparent;border-top:none;border-bottom:none;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| %alpha<math>\rightarrow \alpha </math>
| style="background-color:transparent;border-top:none;border-bottom:none;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| %ALPHA<math>\rightarrow \Alpha </math>

|-
| style="background-color:transparent;border-top:none;border-bottom:none;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| %beta <math>\rightarrow \beta </math>
| style="background-color:transparent;border-top:none;border-bottom:none;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| %BETA <math>\rightarrow \Beta </math>

|-
| style="background-color:transparent;border-top:none;border-bottom:none;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| %gamma<math>\rightarrow \gamma </math>
| style="background-color:transparent;border-top:none;border-bottom:none;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| %GAMMA<math>\rightarrow \Gamma </math>

|-
| style="background-color:transparent;border-top:none;border-bottom:none;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| %psi <math>\rightarrow \psi </math>
| style="background-color:transparent;border-top:none;border-bottom:none;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| %PSI <math>\rightarrow \Psi </math>

|-
| style="background-color:transparent;border-top:none;border-bottom:none;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| %phi <math>\rightarrow \phi </math>
| style="background-color:transparent;border-top:none;border-bottom:none;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| %PHI <math>\rightarrow \Phi </math>

|-
| style="background-color:transparent;border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| %theta<math>\rightarrow \theta </math>
| style="background-color:transparent;border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| %THETA<math>\rightarrow \Theta </math>

|}
Another way to enter Greek characters is by using the Symbols catalog window. Choose '''Tools > Catalog'''. This window is shown in Figure 252. Under ''Symbol set'', select '''Greek''' and double-click on a Greek letter from the list. The markup name of the character is shown below the list window.

<center>[[Image:|thumb|''Figure 252: Symbols catalog, used for entering Greek characters and some special symbols'']]</center>

==== Example 2:<math>\pi \simeq 3.14159</math> ====
For this example we will suppose that:

* We want to enter the above formula (the value of pi rounded to 5 decimal places).
* We know the name of the Greek character (pi).
* But we do not know the markup associated with the <math>\simeq </math> symbol.

'''Step 1''': Type '''%''' followed by the text '''pi'''. This displays the Greek character <math>\pi </math>.

'''Step 2''': Open the Elements window ('''View > Elements''').

'''Step 3''': The <math>\simeq </math> symbol is a relation, so we click on the Relations button. If you hover the mouse over this button you see the tooltip ''Relations'' (Figure 253). 

Figure 254 shows the Selection window after clicking the Relations button. The symbol we want is circled.


{| style="border-spacing:0;"
|| [[Image:]]

''Figure 253: Tooltip indicates the Relations&nbsp;button''
|| [[Image:]]

''Figure 254: After selecting Relations''

|}
'''Step 4''': Click on the a<math>\simeq </math>b symbol. The equation editor now shows the markup '''<nowiki>%pi<?> simeq <?></nowiki>'''.

'''Step 5'''<nowiki>: Delete the <?> text and add </nowiki>'''3.14159''' at the end of the equation. We end up with the markup '''%pi simeq 3.14159'''. The result is shown in Figure 255.

<center>[[Image:|thumb|''Figure 255. Final result'']]</center>

== Customizations ==
=== Formula editor as a floating window ===
The formula editor can cover a large part of the Writer window. To turn the formula editor into a floating window, do this:

# Hover the mouse over the editor frame, as shown in Figure 256.
# Hold down the ''Control'' key and double-click.

<center>[[Image:|thumb|''Figure 256: Turning the formula editor into a floating window'']]</center>

Figure 257 shows the result. You can dock the floating window again by using the same steps. Hold down the ''Control'' key and double-click the window frame.

<center>[[Image:|thumb|''Figure 257: Formula editor as a floating window'']]</center>

=== How can I make a formula bigger? ===
This is one of the most common questions people ask about LibreOffice Math. The answer is simple, but not intuitive:

# Start the formula editor and choose '''Format > Font size'''.

<center>[[Image:|thumb|''Figure 258: Changing the font size for a formula'']]</center>

# Select a larger font size under ''Base size'' (top-most entry).

<center>[[Image:|thumb|''Figure 259. Edit Base size (top) to make a formula bigger'']]</center>

The result of this change is illustrated in Figure 260.

<center>[[Image:|thumb|''Figure 260. Result of changing the base font size'']]</center>

== Formula layout ==
The most difficult part of using LibreOffice Math comes when writing complicated formulas. This section provides some advice.

=== Brackets are your friends ===
LibreOffice Math knows nothing about order of operation. You ''must'' use brackets to state the order of operations explicitly. Consider the following example.


{| style="border-spacing:0;"
! Markup
! Result

|-
| style="background-color:transparent;border-top:none;border-bottom:none;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| 2 over x + 1
| style="background-color:transparent;border-top:none;border-bottom:none;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| <math>\frac{2}{x}+1</math>

|-
| style="background-color:transparent;border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| 2 over {x + 1}
| style="background-color:transparent;border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| <math>\frac{2}{x+1}</math>

|}
=== Equations over more than one line ===
Suppose you want to type an equation covering more than one line. For example:<math>\begin{array}{c}x=3\\ 
y=1\end{array}</math>

Your first reaction would be to simply press the ''Enter'' key. However, if you do this, the markup goes to a new line but the resulting equation does not. You must type the newline command explicitly. This is illustrated in the table below.


{| style="border-spacing:0;"
! Markup
! Result

|-
| style="background-color:transparent;border-top:none;border-bottom:none;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| x = 3

y = 1
| style="background-color:transparent;border-top:none;border-bottom:none;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| <math>x=3y=1</math>

|-
| style="background-color:transparent;border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| x = 3 newline

y = 1
| style="background-color:transparent;border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| <math>\begin{array}{c}x=3\\ 
y=1\end{array}</math>

|}
=== How do I add limits to my sum/integral? ===
The sum and int commands can (optionally) take the parameters ''from'' and ''to''. These are used for lower and upper limits respectively. These parameters can be used singly or together. Limits for integrals are usually treated as subscripts and superscripts.


{| style="border-spacing:0;"
! Markup
! Result

|-
| style="background-color:transparent;border-top:none;border-bottom:none;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| sum from k = 1 to n a_k
| style="background-color:transparent;border-top:none;border-bottom:none;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| <math>\sum _{k=1}^{n}{a}_{k}</math>

|-
| style="background-color:transparent;border-top:none;border-bottom:none;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| int from 0 to x f(t) dt

or 

int_0^x f(t) dt
| style="background-color:transparent;border-top:none;border-bottom:none;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| <math>\underset{0}{\overset{x}{\int }}f\left(t\right)\mathit{dt}</math> or <math>{\int }_{0}^{x}f\left(t\right)\mathit{dt}</math>

|-
| style="background-color:transparent;border-top:none;border-bottom:none;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| int from Re f
| style="background-color:transparent;border-top:none;border-bottom:none;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| <math>\underset{\Re }{\int }f</math>

|-
| style="background-color:transparent;border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| sum to infinity 2^{-n}
| style="background-color:transparent;border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| <math>\sum ^{\infty }{2}^{-n}</math>

|}

{| style="border-spacing:0;"
| style="background-color:#94bd5e;border-top:1pt solid #999999;border-bottom:1pt solid #999999;border-left:none;border-right:none;padding:0.15cm;"| <center>'''Note'''</center>
| style="background-color:transparent;border-top:1pt solid #999999;border-bottom:1pt solid #999999;border-left:none;border-right:none;padding:0.15cm;"| For more details on integrals and sums, see the ''LibreOffice Math Guide''.

|}
=== Brackets with matrices look ugly! ===
For background, we start with an overview of the matrix command.


{| style="border-spacing:0;"
! Markup
! Result

|-
| style="background-color:transparent;border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| matrix { a # b ## c # d }
| style="background-color:transparent;border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| <math>\begin{array}{cc}a& 	b\\ 
c& 	d\end{array}</math>

|}

{| style="border-spacing:0;"
| style="background-color:#94bd5e;border-top:1pt solid #999999;border-bottom:1pt solid #999999;border-left:none;border-right:none;padding:0.15cm;"| <center>'''Note'''</center>
| style="background-color:transparent;border-top:1pt solid #999999;border-bottom:1pt solid #999999;border-left:none;border-right:none;padding:0.15cm;"| Rows are separated by two #’s and entries within each row are separated by one #.

|}
The first problem people have with matrices is that brackets do not scale with the matrix:


{| style="border-spacing:0;"
! Markup
! Result

|-
| style="background-color:transparent;border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| ( matrix { a # b ## c # d } ) 
| style="background-color:transparent;border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| <math>\left(\begin{array}{cc}a& 	b\\ 
c& 	d\end{array}\right)</math>

|}
LibreOffice Math also provides scalable brackets that grow in size to match the size of their contents. Use the commands ''left('' and ''right)'' to make scalable brackets.


{| style="border-spacing:0;"
! Markup
! Result

|-
| style="background-color:transparent;border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| left( matrix { a # b ## c # d } right)
| style="background-color:transparent;border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| <math>\left(\begin{array}{cc}a& 	b\\ 
c& 	d\end{array}\right)</math>

|}

{| style="border-spacing:0;"
| style="background-color:#83caff;border-top:1pt solid #999999;border-bottom:1pt solid #999999;border-left:none;border-right:none;padding:0.15cm;"| <center>'''Tip'''</center>
| style="background-color:transparent;border-top:1pt solid #999999;border-bottom:1pt solid #999999;border-left:none;border-right:none;padding:0.15cm;"| Use ''<nowiki>left[</nowiki>'' and ''right]'' to obtain scalable square brackets.

|}
=== How do I make a derivative? ===
Making derivatives essentially comes down to one trick: ''Tell LibreOffice it’s a fraction''.

In other words, you have to use the ''over'' command. Combine this with either the letter ''d'' (for a total derivative) or the ''partial'' command (for a partial derivative) to achieve the effect of a derivative.


{| style="border-spacing:0;"
| style="background-color:#94bd5e;border-top:1pt solid #999999;border-bottom:1pt solid #999999;border-left:none;border-right:none;padding:0.15cm;"| <center>'''Note'''</center>
| style="background-color:transparent;border-top:1pt solid #999999;border-bottom:1pt solid #999999;border-left:none;border-right:none;padding:0.15cm;"| Notice that we have to use braces (squiggly brackets) to make the derivative.

|}

{| style="border-spacing:0;"
! Markup
! Result

|-
| style="background-color:transparent;border-top:none;border-bottom:none;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| {df} over {dx}
| style="background-color:transparent;border-top:none;border-bottom:none;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| <math>\frac{\mathit{df}}{\mathit{dx}}</math>

|-
| style="background-color:transparent;border-top:none;border-bottom:none;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| {partial f} over {partial y}
| style="background-color:transparent;border-top:none;border-bottom:none;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| <math>\frac{\partial f}{\partial y}</math>

|-
| style="background-color:transparent;border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| {partial^2 f} over {partial t^2}
| style="background-color:transparent;border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| <math>\frac{{\partial }^{2}f}{\partial {t}^{2}}</math>

|}
=== How do I align my equations at the equals sign? ===
LibreOffice Math does not have a command for aligning equations on a particular character, but you can use a matrix to do this, as shown below.


{| style="border-spacing:0;"
! Markup
! Result

|-
| style="background-color:transparent;border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.101cm;"|  matrix{
    alignr x+y # {}={} # alignl 2 ##
    alignr x   <nowiki># {}={} # alignl 2-y</nowiki>
 }
| style="background-color:transparent;border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.101cm;"| <math>\begin{array}{rcl}x+y& 	=& 	2\\ 
x& 	=& 	2-y\end{array}</math>

|}
The empty braces around the = sign are necessary because = is a binary operator and thus needs an expression on each side.

You can reduce the spacing around the = sign by changing the intercolumn spacing of the matrix:

# With the equation editor open, choose '''Format > Spacing''' from the menu bar.
# In the Spacing dialog (Figure 261), click the '''Category''' button and select '''Matrices''' in the drop-down menu.
# Enter '''0%''' for ''Column spacing'' and click '''OK'''.

<center>[[Image:|thumb|''Figure 261: Changing spacing in a matrix formula'']]</center>

== Numbering equations ==
Equation numbering is one of LibreOffice Math’s best hidden features. The steps are simple, but obscure:

# Start a new line.
# Type '''fn''' and then press ''F3''.

The ''fn'' is replaced by a numbered formula:


{| style="border-spacing:0;"
! <center><math>E={\mathit{mc}}^{2}</math> </center>
! <div align="right">(2)</div>

|-

|}
Now you can double-click on the formula to edit it. For example, here is the Riemann Zeta function:


{| style="border-spacing:0;"
! <center><math>\zeta \left(z\right)=\sum _{n=1}^{\infty }\frac{1}{{n}^{z}}</math> </center>
! <div align="right">(3)</div>

|-

|}
You can cross-reference an equation (“as shown in Equation (2)”) with these steps:

# Choose '''Insert > Cross-reference''' from the menu bar.
# On the ''Cross-references'' tab (Figure 262), under ''Type'', select ''Text''.
# Under ''Selection'', select the equation number.
# Under ''Format'', select ''Reference''.
# Click '''Insert'''.

[[Image:|thumb|''Figure 262. Inserting a cross-reference to an equation number '']]

Done! If you later add more equations to the paper before the referenced equation, all the equations will automatically renumber and the cross-references will update.


{| style="border-spacing:0;"
| style="background-color:#83caff;border-top:1pt solid #999999;border-bottom:1pt solid #999999;border-left:none;border-right:none;padding:0.15cm;"| <center>'''Tip'''</center>
| style="background-color:transparent;border-top:1pt solid #999999;border-bottom:1pt solid #999999;border-left:none;border-right:none;padding:0.15cm;"| To insert the equation number without parentheses around it, choose ''Numbering'' under ''Format'' instead of ''Reference.''

|}
== Math commands reference ==
For a full list of the commands available in Math, please see the ''LibreOffice Math Guide''.

* Unary / binary operators
* Relational operators
* Set operations
* Functions
* Operators
* Attributes
* Miscellaneous
* Brackets
* Formats
* Characters – Greek
* Characters – Special


[[Category:LibreOffice 3.4入门|Math入门]]