Regression Analysis III : linest

April 18th, 2005

The third solution to our linear curve fitting problem is to use theLINEST function.

LINEST is an array function - returning an array of parameters extracted from the provided X-Y data.

In the example below, we opt for a minimized set of return parameters and we get the slope and y-intercept values as shown. C29:C31 are the original formulae we saw before. C35:D35 is the array output fromLINEST. Remember to use Ctrl-Shift-Enter when applying this formula.

If array functions make you break out in sweat, you can embedLINEST inside an INDEX to extract whatever return parameter you want. This is also include in the example in C37:C38. Note that INDEXis not an array function - but it likes to work with array functions.

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Rounding to the nearest nickel: mround()

April 7th, 2005

The MROUND function allows you to round to any value you want and is particularly useful in financial/commerce applications where rounding to the nearest nickel/dime/quarter is required. This function is only available if Analysis AddIn is installed. It rounds the target value to any multiple that you specify.

To round the value in A1 to the nearest nickel we use =MROUND(A1; 0.05)

Unlike the equivalent Excel function, MROUND in Calc allows negative numbers.

In fact, MROUND() is so useful - it can even be used to round the time to the nearest quarter hour. An example of this is shown below.

Looking up data in tables V

April 6th, 2005

Here is another simple application of the VLOOKUP function. Consider a sales person who gets paid commissionson sales based on a sliding scale.

For sales up to $50, a comission of 25% is paid, between $50 and $100, the commission drops to 22.5% - and so on. By using the lookup table and VLOOKUP, the correct rate of commission can be applied to each sale.

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Combining data in cells

March 30th, 2005

A few examples showing how data from multiple cells can be combined - as well as how data can be combined with text and with extra formatting. A useful function is the TEXT()( function. We will look at some examples.

A few examples showing how data from multiple cells can be combined - as well as how data can be combined with text and with extra formatting. A useful function is the TEXT()( function. We will look at some examples.

It is straightforward to merge text data from different cells. The & - Ampersand operator is used to concatenate text from different sources. This is shown below in C3

Numerical data can also be combined with text using the & operator - such as in C6 below.

For special data types - such as dates and curencies, we need to use the TEXT() function, which returns a value converted to text with a specified format. A few examples are shown in C9 and C12

Rounding functions I

March 28th, 2005

There are almost a dozen available rounding functions available in OOo Calc. We will first look at ROUND(), ROUNDUP() andROUNDDOWN() Read the rest of this entry »

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