LibreOffice 3.4入门/Math入门
數學是什麼？
编辑數學是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。
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。 
(1) 

讓我們開始吧
编辑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.
Entering a formula
编辑The equation editor uses a markup language to represent formulas. For example, %beta creates the Greek character beta ( ). This markup is designed to read in a similar way to English whenever possible. For example, a over b produces a fraction: .
You can enter a formula in three ways:
 Select a symbol from the Elements window.
 Rightclick 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.
Click on the document body to exit the formula editor.
Doubleclick on a formula to enter the formula editor again. 
The Elements window
编辑The simplest method for entering a formula is the Elements window.
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.
You can hide or show the Elements window with View > Elements. 
Example 1:
编辑For this example we will enter a simple formula: . On the Elements window:
 Select the topleft button of the categories (top) section.
 Click on the multiplication symbol.
When you select the multiplication symbol on the Elements window, two things happen:
 The equation editor shows the markup:
 The body of the document shows a gray box like this:解析失败 (SVG（MathML可通过浏览器插件启用）：从服务器“http://localhost:6011/zh.wikibooks.org/v1/”返回无效的响应（“Math extension cannot connect to Restbase.”）：): {\displaystyle ❑\times ❑}
The <?> symbols shown in 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.
To keep the equation from updating automatically, select View >AutoUpdate display. To update a formula manually, press F9 or select View > Update. 
Rightclick (context) menu
编辑Another way to access mathematical symbols is to rightclick 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.
Markup
编辑You can type the markup directly in the equation editor. For example, you can type 5 times 4 to obtain . If you know the markup, this can be the fastest way to enter a formula.
The formula markup resembles the way the formula reads in English. 
Below is a short list of common equations and their corresponding markup.
Display  Command  Display  Command 

a = b  sqrt {a}  
a^2  a_n  
int f(x) dx  sum a_n  
a <= b  infinity  
a times b  x cdot y 
Greek characters
编辑Greek characters ( , etc) are common in mathematical formulas. These characters are not available in the Elements window or the rightclick 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.
Lowercase  Uppercase 

%alpha  %ALPHA 
%beta  %BETA 
%gamma  %GAMMA 
%psi  %PSI 
%phi  %PHI 
%theta  %THETA 
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 doubleclick on a Greek letter from the list. The markup name of the character is shown below the list window.
Example 2:
编辑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 symbol.
Step 1: Type % followed by the text pi. This displays the Greek character .
Step 2: Open the Elements window (View > Elements).
Step 3: The 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.
[[Image:]]
Figure 253: Tooltip indicates the Relations button 
[[Image:]]
Figure 254: After selecting Relations 
Step 4: Click on the a b symbol. The equation editor now shows the markup %pi<?> simeq <?>.
Step 5: Delete the <?> text and add 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.
Customizations
编辑Formula editor as a floating window
编辑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 doubleclick.
Figure 257 shows the result. You can dock the floating window again by using the same steps. Hold down the Control key and doubleclick the window frame.
How can I make a formula bigger?
编辑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.
 Select a larger font size under Base size (topmost entry).
The result of this change is illustrated in Figure 260.
Formula layout
编辑The most difficult part of using LibreOffice Math comes when writing complicated formulas. This section provides some advice.
Brackets are your friends
编辑LibreOffice Math knows nothing about order of operation. You must use brackets to state the order of operations explicitly. Consider the following example.
Markup  Result 

2 over x + 1  
2 over {x + 1} 
Equations over more than one line
编辑Suppose you want to type an equation covering more than one line. For example:
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.
Markup  Result 

x = 3
y = 1 

x = 3 newline
y = 1 
How do I add limits to my sum/integral?
编辑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.
Markup  Result 

sum from k = 1 to n a_k  
int from 0 to x f(t) dt
or int_0^x f(t) dt 
or 
int from Re f  
sum to infinity 2^{n} 
For more details on integrals and sums, see the LibreOffice Math Guide. 
Brackets with matrices look ugly!
编辑For background, we start with an overview of the matrix command.
Markup  Result 

matrix { a # b ## c # d } 
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:
Markup  Result 

( matrix { a # b ## c # d } ) 
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.
Markup  Result 

left( matrix { a # b ## c # d } right) 
Use left[ and right] to obtain scalable square brackets. 
How do I make a derivative?
编辑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.
Notice that we have to use braces (squiggly brackets) to make the derivative. 
Markup  Result 

{df} over {dx}  
{partial f} over {partial y}  
{partial^2 f} over {partial t^2} 
How do I align my equations at the equals sign?
编辑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.
Markup  Result 

matrix{
alignr x+y # {}={} # alignl 2 ## alignr x # {}={} # alignl 2y } 
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 dropdown menu.
 Enter 0% for Column spacing and click OK.
Numbering equations
编辑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:
(2)


Now you can doubleclick on the formula to edit it. For example, here is the Riemann Zeta function:
(3)


You can crossreference an equation (“as shown in Equation (2)”) with these steps:
 Choose Insert > Crossreference from the menu bar.
 On the Crossreferences tab (Figure 262), under Type, select Text.
 Under Selection, select the equation number.
 Under Format, select Reference.
 Click Insert.
[[Image:thumbFigure 262. Inserting a crossreference 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 crossreferences will update.
To insert the equation number without parentheses around it, choose Numbering under Format instead of Reference. 
Math commands reference
编辑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