10 noviembre Spreadsheets. Unit 3 (Part 3)

Transcription

1 10 noviembre 2011 Spreadsheets Unit 3 (Part 3) 1

2 2 Building Basic Formulas From the simple addition formula to the most complex ANOVA statistical variation, all formulas in Excel have one thing in common: They all begin with the equal sign (=) When building your formulas, you can use constants that actually contain the number that you want used in the calculation (such as 4.5%, $25.00, or ), or you can use cell addresses between the operators or as the arguments of functions. You can use the AutoFill feature to copy a formula by dragging the Fill handle to include the a cell range (for example B8:K8) If you need to convert a relative cell reference to an absolute reference as you re building the original formula, you can convert the relative reference to absolute by selecting the cell and then pressing F4. Also you can use absolute references using the character $ (for example $D$3)

3 3 Building Basic Formulas Operations in Excel

4 4 Building Basic Formulas Operations in Excel (Continue)

5 5 Building Basic Formulas Building an array formula In some cases, you can build the original formula so that Excel performs the desired calculation not only in the active cell, but also in all the other cells to which you would normally copy the formula. You do this by creating an array formula. An array formula is a special formula that operates on a range of values. For example, You can create the following array formula in the array range: ={A4:A7*R4:R7} This array formula multiplies each number of the 4 x 1 array in the range A4:A7 with each number in the 4 x 1 array in the range R4:R7. This same formula is entered into all cells of a array range (for example R10:R13.

6 6 Building Basic Formulas Naming cells, ranges and formulas Although cell references provide a convenient method for pointing out the cell location in the worksheet grid, they are not at all descriptive of their function when used in formulas. Defining range names: You can define a name for the selected cell range or nonadjacent selection by typing its range name into the Name box on the Formula bar. Naming constants and formulas: you can also assign range names to the constants and formulas that you use often Creating names from column and row headings: You can use the Create from Selection command button on the Formulas tab of the Ribbon to assign existing column and row headings in a table of data to the cells in that table

7 7 Error Trapping If Excel can t properly calculate a formula that you enter in a cell, the pro- gram displays an error value in the cell as soon as you complete the formula entry Excel uses several error values, all of which begin with the number sign (#).

8 8 Error Trapping (Continue)

9 9 Logical Functions Excel uses the following logical functions, which appear on the Logical command button s drop-down menu on the Formulas tab of the Ribbon AND(logical1,logical2,...) tests whether the logical arguments are TRUE or FALSE. If they are all TRUE, the AND function returns TRUE to the cell. If any are FALSE, the AND function returns FALSE. FALSE() takes no argument and simply enters logical FALSE. IF(logical_test,value_if_true,value_if_false) tests whether the logical_test expression is TRUE or FALSE. IFERROR(value,value_if_error) returns the value argument when the cell doesn t contain an error value and the value_if_error argument when it does. NOT(logical) tests whether the logical argument is TRUE or FALSE. If TRUE, the NOT function returns FALSE to the cell and vice versa OR(logical1,logical2,...) tests whether the logical arguments are TRUE or FALSE. If any are TRUE, the OR function returns TRUE. Other case, returns FALSE. TRUE() takes no argument and simply enters logical TRUE in its cell

10 10 Date and Time Formulas Most of the date formulas that you build are designed to calculate the number of days or years that have elapsed between two dates Excel contains a number of built-in date functions that you can use in your spreadsheets TODAY() DATE(year,month,day) DAY(serial_number) MONTH(serial_number) YEAR(serial_number) WEEKDAY(serial_number,[return_type]) DAYS360(start_date,end_date,[method]) EDATE(start_date,months) EOMONTH(date) NETWORKDAYS(start_date,end_date,[hd]) WEEKNUM(serial_number,[return_type]) WORKDAY(start_date,days,[holidays]) YEARFRAC(start_date,end_date,[basis]) NOW() TIME(hour,minute,second) HOUR(number) MINUTE (number) SECOND (number)

11 11 Math Formulas Rounding off numbers: You use the ROUND function to round up or down fractional values in the worksheet as you might. ROUND(number,num_digits) Instead of the ROUND function, you can use the ROUNDUP or ROUNDDOWN function. Both take the same number and num_digits arguments as the ROUND function. The TRUNC function uses the same number and num_digits arguments as the ROUND. The EVEN function rounds the value specified as its number argument up to the nearest even integer. The ODD function, of course, does just the opposite: rounding the value up to the nearest odd integer The CEILING function enables you to round up a number, and also set the multiple of significance to be used when doing the rounding.

12 12 Math Formulas POWER and SQRT Although you can use the caret (^) operator to build a formula that raises a number to any power, you also need to be aware that Excel includes a math function called POWER The SQRT enables you to calculate the square root of any number that you specify as its sole number argument The SUM of the parts SUM(number1,[number2],[...]) When using the SUM function, only the number1 argument is required; this is the range of numbers in a cell range or array constant that you want added together The SUMIF function enables you to tell Excel to add together the numbers in a particular range only when those numbers meet the criteria that you specify

13 13 Statistical Formulas AVERAGE, MAX, and MIN: All three functions follow the same syntax as the good old SUM function: AVERAGE(number1, [number2],[...]) Counting cells The most basic formula is the one that returns the total number of cells in a specific range. To build this formula in a cell, we use the ROWS and COLUMNS information functions. We can calculate the number of that cells that contain data entries (of whatever type) using the COUNTA function The COUNT function takes the same arguments as COUNTA, the only difference being that COUNT counts a value or cell specified in its value arguments only if it contains a numeric entry. COUNTBLANK calculates the number of blank cells in a range Excel includes a COUNTIF function that you can use to count cells in a range only when they meet a certain condition