Degrees of polynomial in charts

[qlikviewwizard]

Hi All, When will you  use Polynomial 2nd 3rd or 4th degree in charts? Thanks in advance.

[qlikmsg4u]

Expression tab:

Trendlines

In selected QlikView charts expression plots can be complemented or replaced by statistical trend lines. Trend lines can only be displayed in scatter charts, line charts and in bar/combo charts with maximally one dimension and one expression shown as bars. For other types of charts, the settings in the Trendlines group are unavailable and have no effect. In scatter charts the data points are treated as if y=f(x). For bar, line and combo charts it is allowed to deselect all options under Display Options and still add trend lines, which will then be plotted without the underlying data points. Trend lines in bar, line and combo charts may be extrapolated by specifying a forecastand/or backcast interval (Axes page). The extrapolated lines will be dotted. Trend lines in charts with a discrete x-axis will be shown as lines with symbols. On a continuous axis only the line will be shown.Average The average is plotted as a straight line. Linear A linear regression line is plotted. Polynomial of 2nd degree A polynomial trend line of the second degree is plotted. Polynomial of 3rd degree A polynomial trend line of the third degree is plotted. Polynomial of 4th degree A polynomial trend line of the fourth degree is plotted. Exponential An exponential trend line is plotted. Show Equation If this check box is marked for a specific expression, the expression’s trend lines will be complemented by the trendline equation expressed as text in the chart. Show R2 If this check box is marked for a specific expression, the expression’s trend lines will be complemented by the coefficient of determination expressed as text in the chart.

Axis tab:

Backcast	This function operates on trend lines. Enter into the text edit box how far back you would like to estimate the trend line. See Chart Properties: Expressions. The backcast portion of trend lines is displayed as dotted.
Forecast	Enter into the text edit box how far you wish to predict the trend line. See Chart Properties: Expressions. The forecast portion of trend lines is displayed as dotted.

[Kushal_Chawda]

We use this option for Forecasting. Please find the below details taken from QlikView reeference manual

In selected QlikView charts expression plots can be complemented or replaced

by statistical trend lines. Trend lines can only be displayed in scatter charts,

line charts and in bar/combo charts with maximally one dimension and one

expression shown as bars. For other types of charts, the settings in the Trendlines

group are unavailable and have no effect. In scatter charts the data points

are treated as if y=f(x). For bar, line and combo charts it is allowed to deselect

all options under Display Options and still add trend lines, which will then be

plotted without the underlying data points. Trend lines in bar, line and combo

charts may be extrapolated by specifying a forecast and/or backcast interval

(Axes page). The extrapolated lines will be dotted. Trend lines in charts with a

discrete x-axis will be shown as lines with symbols. On a continuous axis

only the line will be shown.

Average

The average is plotted as a straight line.

Linear

A linear regression line is plotted.

Polynomial of 2nd degree

A polynomial trend line of the second degree is plotted.

Polynomial of 3rd degree

A polynomial trend line of the third degree is plotted.

Polynomial of 4th degree

A polynomial trend line of the fourth degree is plotted.

Exponential

An exponential trend line is plotted.

Show Equation

If this check box is marked for a specific expression, the expression’s trend

lines will be complemented by the trendline equation expressed as text in the

chart.

Show R2

If this check box is marked for a specific expression, the expression’s trend

lines will be complemented by the coefficient of determination expressed as

text in the chart.

[qlikviewwizard]

Hi, Could you please give an example of qvw? Thank you.

[jagan]

Hi,

Check this link for some basic stuff with examples, then you can easily understand it in Qlikview. 

Degree (of an Expression)

Regards,

Jagan.

[qlikviewwizard]

Hi Jagan, As a science student, I was worked on this in academics.Could you please provide an example where we use in Qlikview develpment? Thank you.

[jagan]

Hi,

In some statistical dashboards users request to add this polynomial, not sure how it really helps for them.  But in Qlikview charts it is straight forward, just need to select option in Trendlines section of Expression tab.

Hope this helps you.

Regards,

Jagan.