Part 5: Creating Formulas and Performing Data Analysis in Visual C#.NET

Drawer QR in Visual C#.NET Part 5: Creating Formulas and Performing Data Analysis

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Figure 13-4. Choose Tools, Add-Ins to install the Analysis ToolPak, which includes (among other things) the Tools, Data Analysis command, whose dialog box is shown on the right.

Worksheet functions have two parts: the name of the function and the argument(s) that follow. Function names such as SUM and AVERAGE describe the operation that the function performs. Arguments specify the values or cells to be used by the function. For example, the function ROUND has the following syntax: =ROUND(number, num_digits) as in the formula =ROUND(M30,2). The M30 is a cell reference entered as the number argument the value to be rounded. The 2 is the num_digits argument. The result of this function is a number (whatever M30 happens to be) rounded to two decimal places. Parentheses surround function arguments. The opening parenthesis must appear immediately after the name of the function. If you add a space or some other character between the name and the opening parenthesis, the error value #NAME appears in the cell. Note A few functions, such as PI, TRUE, and NOW have no arguments. (These functions are usually nested in other formulas.) Even though they have no arguments, they must be followed by an empty set of parentheses, as in =NOW( ). When you use more than one argument in a function, you separate the arguments with commas. For example, the formula =PRODUCT(C1,C2,C5) tells Excel to multiply the numbers in cells C1, C2, and C5. Some functions, like PRODUCT and SUM, take an unspecified number of arguments. You can use as many as 30 arguments in a function, as long as the total length of the formula does not exceed 1,024 characters. However, you can use a single argument, or a range that refers to any number of cells in your worksheet, as a formula. For example, the function =SUM(A1:A5,C2:C10,D3:D17) has only three arguments but actually totals the values in 29 cells. (The first argument, A1:A5, refers to the range of five cells from 404

Using Functions A1 through A5, and so on.) The referenced cells can, in turn, also contain formulas that refer to more cells or ranges.

You can use combinations of functions to create an expression that Excel evaluates to a single value and then interprets as an argument. For example, in the formula =SUM(SIN(A1*PI( )),2*COS(A2*PI( ))) the comma separates two complex expressions that are evaluated and used as the arguments of the SUM function.

In the examples presented so far, all the arguments have been cell or range references. You can also use numbers, text, logical values, range names, arrays, and error values as arguments.

The arguments to a function can be numeric. For example, the SUM function in the formula =SUM(327,209,176) adds the numbers 327, 209, and 176. Usually, however, you enter the numbers you want to use in cells of a worksheet and then use references to those cells as arguments to your functions.

You can also use text as an argument to a function. For example, in the formula =TEXT(NOW( ),"mmm d, yyyy") in the second argument to the TEXT function, mmm d, yyyy, is a text argument specifically recognized by Excel. It specifies a pattern for converting the serial date value returned by NOW into a text string. Text arguments can be text strings enclosed in quotation marks or references to cells that contain text.

The arguments to a few functions specify only that an option is either set or not set; you can use the logical values TRUE to set an option and FALSE to specify that the option isn t set. A logical expression returns the value TRUE or FALSE to the worksheet or the formula containing the expression. For example, the first argument of the IF function in the formula =IF(A1=TRUE,"Future ", "Past ")&"History" is a logical expression that uses the value in cell A1. If the value in A1 is TRUE, the expression A1=TRUE evaluates to TRUE, the IF function returns Future, and the formula returns the text Future History to the worksheet.