Wednesday, December 10, 2008

 

 

EXCAL FORMULAS

Array Formulas Many of the formulas described here are Array Formulas, which are a special type of formula in Excel. If you are not familiar with Array Formulas, click here. Array To Column Sometimes it is useful to convert an MxN array into a single column of data, for example for charting (a data series must be a single row or column). Click here for more details. Averaging Values In A Range You can use Excel’s built in =AVERAGE function to average a range of values. By using it with other functions, you can extend its functionality. For the formulas given below, assume that our data is in the range A1:A60. Averaging Values Between Two Numbers Use the array formula =AVERAGE(IF((A1:A60>=Low)*(A1:A60<=High),A1:A60)) Where Low and High are the values between which you want to average. Averaging The Highest N Numbers In A Range To average the N largest numbers in a range, use the array formula =AVERAGE(LARGE(A1:A60,ROW(INDIRECT(“1:10”)))) Change “1:10” to “1:N” where N is the number of values to average. Averaging The Lowest N Numbers In A Range To average the N smallest numbers in a range, use the array formula =AVERAGE(SMALL(A1:A60,ROW(INDIRECT(“1:10”)))) Change “1:10” to “1:N” where N is the number of values to average. In all of the formulas above, you can use =SUM instead of =AVERAGE to sum, rather than average, the numbers. Counting Values Between Two Numbers If you need to count the values in a range that are between two numbers, for example between 5 and 10, use the following array formula: =SUM((A1:A10>=5)*(A1:A10<=10)) Excel Formulas 􀀀 Created by 􀀀 PRADEEP To sum the same numbers, use the following array formula: =SUM((A1:A10>=5)*(A1:A10<=10)*A1:A10) Counting Characters In A String The following formula will count the number of “B”s, both upper and lower case, in the string in B1. =LEN(B1)-LEN(SUBSTITUTE(SUBSTITUTE(B1,”B”,””),”b”,””)) Date And Time Formulas A variety of formulas useful when working with dates and times are described on the DateTime page. Other Date Related Procedures are described on the following pages. Adding Months And Years The DATEDIF Function Date Intervals Dates And Times Date And Time Entry Holidays Julian Dates Duplicate And Unique Values In A Range The task of finding duplicate or unique values in a range of data requires some complicated formulas. These procedures are described in Duplicates. Dynamic Ranges You can define a name to refer to a range whose size varies depending on its contents. For example, you may want a range name that refers only to the portion of a list of numbers that are not blank. such as only the first N non-blank cells in A2:A20. Define a name called MyRange, and set the Refers To property to: =OFFSET(Sheet1!$A$2,0,0,COUNTA($A$2:$A$20),1) Be sure to use absolute cell references in the formula. Also see then Named Ranges page for more information about dynamic ranges. Finding The Used Part Of A Range Suppose we’ve got a range of data called DataRange2, defined as H7:I25, and that cells H7:I17 actually contain values. The rest are blank. We can find various properties of the range, as follows: To find the range that contains data, use the following array formula: =ADDRESS(ROW(DataRange2),COLUMN(DataRange2),4)&”:”& ADDRESS(MAX((DataRange2<>””)*ROW(DataRange2)),COLUMN(DataRange2)+ COLUMNS(DataRange2)-1,4) This will return the range H7:I17. If you need the worksheet name in the returned range, use the following array formula: =ADDRESS(ROW(DataRange2),COLUMN(DataRange2),4,,”MySheet”)&”:”& ADDRESS(MAX((DataRange2<>””)*ROW(DataRange2)),COLUMN(DataRange2)+ COLUMNS(DataRange2)-1,4) This will return MySheet!H7:I17. To find the number of rows that contain data, use the following array formula: =(MAX((DataRange2<>””)*ROW(DataRange2)))-ROW(DataRange2)+1 This will return the number 11, indicating that the first 11 rows of DataRange2 contain data. To find the last entry in the first column of DataRange2, use the following array formula: =INDIRECT(ADDRESS(MAX((DataRange2<>””)*ROW(DataRange2)), COLUMN(DataRange2),4)) To find the last entry in the second column of DataRange2, use the following array formula: =INDIRECT(ADDRESS(MAX((DataRange2<>””)*ROW(DataRange2)), COLUMN(DataRange2)+1,4)) First And Last Names Suppose you’ve got a range of data consisting of people’s first and last names. There are several formulas that will break the names apart into first and last names separately. Suppose cell A2 contains the name “John A Smith”. To return the last name, use =RIGHT(A2,LEN(A2)-FIND(“*”,SUBSTITUTE(A2,” “,”*”,LEN(A2)- LEN(SUBSTITUTE(A2,” “,””))))) To return the first name, including the middle name (if present), use =LEFT(A2,FIND(“*”,SUBSTITUTE(A2,” “,”*”,LEN(A2)- LEN(SUBSTITUTE(A2,” “,””))))-1) To return the first name, without the middle name (if present), use =LEFT(B2,FIND(“ “,B2,1)) We can extend these ideas to the following. Suppose A1 contains the string “First Second Third Last”. Returning First Word In A String =LEFT(A1,FIND(“ “,A1,1)) This will return the word “First”. Returning Last Word In A String =RIGHT(A1,LEN(A1)-MAX(ROW(INDIRECT(“1:”&LEN(A1))) *(MID(A1,ROW(INDIRECT(“1:”&LEN(A1))),1)=” “))) This formula in as array formula. (This formula comes from Laurent Longre). This will return the word “Last” Returning All But First Word In A String =RIGHT(A1,LEN(A1)-FIND(“ “,A1,1)) This will return the words “Second Third Last” Returning Any Word Or Words In A String The following two array formulas come compliments of Laurent Longre. To return any single word from a single-spaced string of words, use the following array formula: =MID(A10,SMALL(IF(MID(“ “&A10,ROW(INDIRECT (“1:”&LEN(A10)+1)),1)=” “,ROW(INDIRECT(“1:”&LEN(A10)+1))), B10),SUM(SMALL(IF(MID(“ “&A10&” “,ROW(INDIRECT (“1:”&LEN(A10)+2)),1)=” “,ROW(INDIRECT(“1:”&LEN(A10)+2))), B10+{0,1})*{-1,1})-1) Where A10 is the cell containing the text, and B10 is the number of the word you want to get. This formula can be extended to get any set of words in the string. To get the words from M for N words (e.g., the 5th word for 3, or the 5th, 6th, and 7th words), use the following array formula: =MID(A10,SMALL(IF(MID(“ “&A10,ROW(INDIRECT (“1:”&LEN(A10)+1)),1)=” “,ROW(INDIRECT(“1:”&LEN(A10)+1))), B10),SUM(SMALL(IF(MID(“ “&A10&” “,ROW(INDIRECT (“1:”&LEN(A10)+2)),1)=” “,ROW(INDIRECT(“1:”&LEN(A10)+2))), B10+C10*{0,1})*{-1,1})-1) Where A10 is the cell containg the text, B10 is the number of the word to get, and C10 is the number of words, starting at B10, to get. Note that in the above array formulas, the {0,1} and {-1,1} are enclosed in array braces (curly brackets {} ) not parentheses. Download a workbook illustrating these formulas. Grades A frequent question is how to assign a letter grade to a numeric value. This is simple. First create a define name called “Grades” which refers to the array: ={0,”F”;60,”D”;70,”C”;80,”B”;90,”A”} Then, use VLOOKUP to convert the number to the grade: =VLOOKUP(A1,Grades,2) where A1 is the cell contains the numeric value. You can add entries to the Grades array for other grades like C- and C+. Just make sure the numeric values in the array are in increasing order. High And Low Values You can use Excel’s Circular Reference tool to have a cell that contains the highest ever reached value. For example, suppose you have a worksheet used to track team scores. You can set up a cell that will contain the highest score ever reached, even if that score is deleted from the list. Suppose the score are in A1:A10. First, go to the Tools->Options dialog, click on the Calculation tab, and check the Interations check box. Then, enter the following formula in cell B1: =MAX(A1:A10,B1) Cell B1 will contian the highest value that has ever been present in A1:A10, even if that value is deleted from the range. Use the =MIN function to get the lowest ever value. Another method to do this, without using circular references, is provided by Laurent Longre, and uses the CALL function to access the Excel4 macro function library. Click here for details. Left Lookups The easiest way do table lookups is with the =VLOOKUP function. However, =VLOOKUP requires that the value returned be to the right of the value you’re looking up. For example, if you’re looking up a value in column B, you cannot retrieve values in column A. If you need to retrieve a value in a column to the left of the column containing the lookup value, use either of the following formulas: =INDIRECT(ADDRESS(ROW(Rng)+MATCH(C1,Rng,0)-1,COLUMN(Rng)- ColsToLeft)) Or =INDIRECT(ADDRESS(ROW(Rng)+MATCH(C1,Rng,0)-1,COLUMN(A:A) )) Where Rng is the range containing the lookup values, and ColsToLeft is the number of columns to the left of Rng that the retrieval values are. In the second syntax, replace “A:A” with the column containing the retrieval data. In both examples, C1 is the value you want to look up. See the Lookups page for many more examples of lookup formulas. Minimum And Maximum Values In A Range Of course you can use the =MIN and =MAX functions to return the minimum and maximum values of a range. Suppose we’ve got a range of numeric values called NumRange. NumRange may contain duplicate values. The formulas below use the following example: Address Of First Minimum In A Range To return the address of the cell containing the first (or only) instance of the minimum of a list, use the following array formula: =ADDRESS(MIN(IF(NumRange=MIN(NumRange),ROW(NumRange))),COLUMN(NumRange),4) This function returns B2, the address of the first ‘1’ in the range. Address Of The Last Minimum In A Range To return the address of the cell containing the last (or only) instance of the minimum of a list, use the following array formula: =ADDRESS(MAX(IF(NumRange=MIN(NumRange),ROW(NumRange)*(NumRange<>””))), COLUMN(NumRange),4) This function returns B4, the address of the last ‘1’ in the range. Address Of First Maximum In A Range To return the address of the cell containing the first instance of the maximum of a list, use the following array formula: =ADDRESS(MIN(IF(NumRange=MAX(NumRange),ROW(NumRange))),COLUMN(NumRange),4) This function returns B1, the address of the first ‘5’ in the range. Address Of The Last Maximum In A Range To return the address of the cell containing the last instance of the maximum of a list, use the following array formula: =ADDRESS(MAX(IF(NumRange=MAX(NumRange),ROW(NumRange)*(NumRange<>””))), COLUMN(NumRange),4) This function returns B5, the address of the last ‘5’ in the range. Download a workbook illustrating these formulas. Most Common String In A Range The following array formula will return the most frequently used entry in a range: =INDEX(Rng,MATCH(MAX(COUNTIF(Rng,Rng)),COUNTIF(Rng,Rng),0)) Where Rng is the range containing the data. Ranking Numbers Often, it is useful to be able to return the N highest or lowest values from a range of data. Suppose we have a range of numeric data called RankRng. Create a range next to RankRng (starting in the same row, with the same number of rows) called TopRng. Also, create a named cell called TopN, and enter into it the number of values you want to return (e.g., 5 for the top 5 values in RankRng). Enter the following formula in the first cell in TopRng, and use Fill Down to fill out the range: =IF(ROW()-ROW(TopRng)+1>TopN,””,LARGE(RankRng,ROW()- ROW(TopRng)+1)) To return the TopN smallest values of RankRng, use =IF(ROW()-ROW(TopRng)+1>TopN,””,SMALL(RankRng,ROW()- ROW(TopRng)+1)) The list of numbers returned by these functions will automatically change as you change the contents of RankRng or TopN. Download a workbook illustrating these formulas. See the Ranking page for much more information about ranking numbers in Excel. Removing Blank Cells In A Range The procedures for creating a new list consisting of only those entries in another list, excluding blank cells, are described in NoBlanks. Summing Every Nth Value You can easily sum (or average) every Nth cell in a column range. For example, suppose you want to sum every 3rd cell. Suppose your data is in A1:A20, and N = 3 is in D1. The following array formula will sum the values in A3, A6, A9, etc. =SUM(IF(MOD(ROW($A$1:$A$20),$D$1)=0,$A$1:$A$20,0)) If you want to sum the values in A1, A4, A7, etc., use the following array formula: =SUM(IF(MOD(ROW($A$1:$A$20)-1,$D$1)=0,$A$1:$A$20,0)) If your data ranges does not begin in row 1, the formulas are slightly more complicated. Suppose our data is in B3:B22, and N = 3 is in D1. To sum the values in rows 5, 8, 11, etc, use the following array formula: =SUM(IF(MOD(ROW($B$3:$B$22)-ROW($B$3)+1,$D$1)=0,$B$3:B$22,0)) If you want to sum the values in rows 3, 6, 9, etc, use the following array formula: =SUM(IF(MOD(ROW($B$3:$B$22)-ROW($B$3),$D$1)=0,$B$3:B$22,0)) Download a workbook illustrating these formulas. Miscellaneous Sheet Name Suppose our active sheet is named “MySheet” in the file C:\Files\MyBook.Xls. To return the full sheet name (including the file path) to a cell, use =CELL(“filename”,A1) Note that the argument to the =CELL function is the word “filename” in quotes, not your actual filename. This will return “C:\Files\[MyBook.xls]MySheet” To return the sheet name, without the path, use =MID(CELL(“filename”,A1),FIND(“]”,CELL(“filename”,A1))+1, LEN(CELL(“filename”,A1))-FIND(“]”,CELL(“filename”,A1))) This will return “MySheet” File Name Suppose our active sheet is named “MySheet” in the file C:\Files\MyBook.Xls. To return the file name without the path, use =MID(CELL(“filename”,A1),FIND(“[“,CELL(“filename”,A1))+1,FIND(“]”, CELL(“filename”,A1))-FIND(“[“,CELL(“filename”,A1))-1) This will return “MyBook.xls” To return the file name with the path, use either =LEFT(CELL(“filename”,A1),FIND(“]”,CELL(“filename”,A1))) Or =SUBSTITUTE(SUBSTITUTE(LEFT(CELL(“filename”,A1),FIND(“]”, CELL(“filename”,A1))),”[“,””),”]”,””) The first syntax will return “C:\Files\[MyBook.xls]” The second syntax will return “C:\Files\MyBook.xls” In all of the examples above, the A1 argument to the =CELL function forces Excel to get the sheet name from the sheet containing the formula. Without it, and Excel calculates the =CELL function when another sheet is active, the cell would contain the name of the active sheet, not the sheet actually containing the formula. Testing whether conditions are true or false and making logical comparisons between expressions are common to many tasks. You can use the AND, OR, NOT, and IF function to create conditional formulas. The IF function uses the following arguments. Formula with the IF function logical_test: The condition that you want to check. value_if_true: The value to return if the condition is true. value_if_false: The value to return if the condition is false. What do you want to do? Create a conditional formula that results in a logical value (TRUE or FALSE) Create a conditional formula that results in another calculation or in values other than TRUE or FALSE Create a conditional formula that results in a logical value (TRUE or FALSE) To do this task, use the AND, OR, and NOT functions, and operators (operator: A sign or symbol that specifies the type of calculation to perform within an expression. There are mathematical, comparison, logical, and reference operators.). Example The example may be easier to understand if you copy it to a blank worksheet. How to copy an example Create a blank workbook or worksheet. Select the example in the Help topic. Note Do not select the row or column headers. Selecting an example from Help Press CTRL+C. In the worksheet, select cell A1, and press CTRL+V. To switch between viewing the results and viewing the formulas that return the results, press CTRL+‘ (grave accent), or on the Tools menu, point to Formula Auditing, and then click Formula Auditing Mode. A Data 15 9 8 Sprockets Widgets Formula Description (Result) =AND(A2>A3, A2A3, A2”Sprockets”,A6 = “Widgets”) Is A5 not equal to “Sprockets” or A6 equal to “Widgets”? (TRUE) Function details AND OR NOT Top of Page Create a conditional formula that results in another calculation or in values other than TRUE or FALSE To do this task, use the IF, AND, and OR functions. Example The example may be easier to understand if you copy it to a blank worksheet. How to copy an example Create a blank workbook or worksheet. Select the example in the Help topic. Note Do not select the row or column headers. Selecting an example from Help Press CTRL+C. In the worksheet, select cell A1, and press CTRL+V. To switch between viewing the results and viewing the formulas that return the results, press CTRL+‘ (grave accent), or on the Tools menu, point to Formula Auditing, and then click Formula Auditing Mode. A Data 15 9 8 Sprockets Widgets Formula Description (Result) =IF(A2=15, “OK”, “Not OK”) If the value in cell A2 equals 15, then return “OK”. (OK) =IF(A2<>15, “OK”, “Not OK”) If the value in cell A2 is not equal to 15, then return “OK”. (Not OK) =IF(NOT(A2<=15), “OK”, “Not OK”) If the value in cell A2 is not less than or equal to 15, then return “OK”. (Not OK) =IF(A5<>”SPROCKETS”, “OK”, “Not OK”) If the value in cell A5 is not equal to “SPROCKETS”, then return “OK”. (Not OK) =IF(AND(A2>A3, A2A3, A2<>A4), “OK”, “Not OK”) If 15 is not equal to 9 and 15 is not equal to 8, then return “OK”. (OK) 2 =IF(OR(A2>A3, A2”Sprockets”, A6<>”Widgets”), “OK”, “Not OK”) If the value in cell A5 is not equal to “Sprockets” or “Widgets”, then return “OK”. (Not OK) 4 =IF(OR(A2<>A3, A2<>A4), “OK”, “Not OK”) If 15 is not equal to 9 or 15 is not equal to 8, then return “OK”. (OK)

 

How to Partition the Hard Disk Drive

Using Disk Management under Windows 2000/XP Note: The external hard disk drive cannot work with the “Dynamic” disk type. Do not upgrade the external hard disk to drive “Dynamic” disk type, always use it with “Basic” disk type. 1. To partition the external hard disk drive under Windows 2000 or Windows XP, please plug in the external hard disk drive and make sure it is recognized and then: ♦ In Windows 2000: click Start 􀃖 Settings 􀃖 Control Panel 􀃖 Administrative Tools 􀃖 Computer Management, then the “Computer Management” window will be opened. ♦ In Windows XP: click Start 􀃖 Control Panel 􀃖 Performance and Maintenance 􀃖 Administrative Tools 􀃖 Computer Management, then the “Computer Management” window will be opened. 2. Click on “Disk Management” on the left part of this window, all connected disk drives will be listed in the right part. Find out the Disk # that indicates the external hard disk drive, for example, on the following picture, “Disk 1” is the external hard disk drive. On the right side of the “Disk 1” is the status of the partitions of this drive, you can create a new or delete an existing partition by right-clicking on this area. The following steps will describe how to create a new partition on this external hard disk drive. Note: If the hard disk drive in the external enclosure is a new unpartioned drive, a “Stop” mark will indicate this drive is an “Unknown” type of disk (refer to the figure shown on the right side) when “Disk Management” is opened. In this situation, the Windows system will not allow you to create a partition with this drive. In this case, you can: ♦ In Windows 2000: Windows will start up the “Write Signature and Upgrade Disk Wizard” immediately. You can use this wizard to initialize the hard disk drive to the “Basic” disk type and can then create partition in the drive. ♦ In Windows XP: you can right-click on the “Stop” mark, and then click “Initialize disk” to initialize the hard disk drive to the “Basic” disk type and can then create partition in the drive. 3. If the type of the hard disk drive is “Dynamic”, you must change it to the “Basic” type. To do this, rightclick on “Disk 1”, and then click “Revert to Basic Disk” from the options. Wait for a few seconds, the type of the hard disk drive will be then changed to “Basic” type. 4. To create a new partition in the hard disk drive, right-click on the partition area (right area) of “Disk 1”, then click on “Create Partition…”, the “Create Partition Wizard” appears, click Next. 5. Select “Primary partition”, click Next. 6. Specify the size that you want this partition to be, click Next. 7. Assign a drive letter for this partition, please use the default value, and click Next. 8. Refer to the figure shown below, select “Format this partition with the following settings”, choose the file system, and specify a name for the volume label, select “Perform a Quick Format”, then, click Next. Click Finish to start the formatting, after the process is done, the “Disk Management” window is changed as below. Make sure the status of the partition is “Healthy”. 10. Now, a partition is created in the external hard disk drive, data can now be written to it. If desired, one or more partitions can be created in the same drive. For this, just repeat the steps above. Using FDISK under Windows 98SE/Me FDISK is a program to create one or more partitions in the hard disk drive. (Data can only be written to the drive after this is partitioned and formatted.) To partition the external hard disk drive, you must execute FDISK under the MS-DOS mode under Windows 98SE/Me, please follow these steps: 1. Boot-up the computer into Windows 98SE/Me system. Plug the external hard disk drive to computer, and make sure it is recognized. 2. Go into the MS-DOS mode by click on Start 􀃖 Programs 􀃖 MS-DOS Prompt. 3. At the DOS prompt, type “FDISK” and press Enter. 4. In the first screen of FDISK, answer the question: “Do you want to enable large disk support?” Y if you want to create a partition larger than 2GB (FAT32). N if you want to create a partition small than 2GB (FAT16). 5. The next screen is “FDISK OPTIONS”. You must type 5 on this screen to change the current fixed disk drive, the default fixed drive set by FDISK is the internal hard disk drive. If you do not change it to the external hard disk drive, the data of internal hard disk drive will be destroyed. If the option 5 does not appear on this screen, it means the external hard disk drive is not installed properly, please check the software installation. 6. In “Change Current Fixed Disk Drive” screen, type the disk drive number that is assigned to the external hard disk drive (usually, the external hard disk drive is the fixed disk drive number 2). 7. Back to “FDISK OPTIONS” screen, type 4 to display the content of the fixed disk drive, check the content to make sure the current drive is the external hard disk drive. 8. Now you can create (type 1) or delete (type 3) the partition of the external hard disk drive. 9. After you finish FDISK, reboot computer to activate the chan

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