# Performance analysis

## Overview

The Performance analysis calculates the performance of a time series compared to a point in the past. The performance can be measured as a percentage change, the level of the change or as a logarithmic change.

## Settings

#### Changed since

Specify the starting point of the calculations.

*Please note that the performance will be calculated relative the first value before the specified starting point.*

###### Year to date, Quarter to date, Month to date, Week to date

Calculate the performance during a year, quarter, month or week. A date can specify a period of choice. If no date is specified, the last period of the series will be used.

###### Years back, Quarter back, Months back, Weeks back

Calculate the performance for the last years, quarters, months or weeks. Specify the number of periods.

###### Specific date

Calculate the performance starting at a specific date until the end of the series.

#### Method

###### Value

Calculate the change in value over the time period.

$y\left(t\right)=z\left(t+h\right)-z\left(t\right)$###### Percentage

Calculate the percentage change over the time period.

$y\left(t\right)=100\frac{z\left(t+h\right)-z\left(t\right)}{\left|\text{z}\left(t\right)\right|}$###### Logarithm

Calculate the logarithmic percentage change over the time period.

$y\left(t\right)=100\cdot \text{ln}\frac{z\left(t+h\right)}{z\left(t\right)}$