**linear regression u . nonlinear functions**

with LINREG them is a useful application of the method of least squares are available - the description of a set of experimental data by a curve or a theoretical formula to obtain a linear or non - linear relationship which best fits the data - when possible small errors .

**LinReg consists of the parts of the program :**

- linear regression
- Nonlinear functions - straight - equations

**applications:**

Evaluation of measured values and detecting the measured value characteristic

Calibration of measurement systems by linear regression

Detecting contexts within a series of studies

Representation of processes with linear or non- linear relation

Calculating a mathematical equation by y = ax + b or optionally for a non - linear relationship until 9 polynomial by:

Y = A0 + + a2x2 a1x + a3x3 ..... + amxm

Creating a formula from a value table

Examples : - Creation of characteristics for pumps

- Calibration curves for Photometry - polarimetry - AAS - etc.

- Preparation of performance curves for machines ,

graphical representation of curves with manual change possibility of coefficients

Creating a mathematical relation of graphic templates for acquisition

in computer programs

**linear regression**

**calculations:**

- Mathematical relationship of value pairs as a function of x by:

f ( x) = ax + b for straight lines with and without intercept ( b = 0) possibility

calculating force with by 0/0

- Error for the slope and intercept .

- Error for each measured value in % and absolute.

- Correlation coefficient.

Graphical representation of the calculated function on the screen - at variable

Axis geometry

In order to optimize the calculation of additional pairs of values can be appended , deleted or changed .

**non-linear functions**

For the presentation of functions and technical processes with mathematical operations in a non-linear curve.

Creating a formula from a value table with nonlinear history

Detection of operations with non-linear character

**Applications**:

- Creation of curves or absorption curves

- Performance curves for machines

- Forming Calculations n in a degree function.

For a number of measurements a mathematical function is calculated to 9 polynomial.

Graphical representation of the calculated function on the screen

**Line equations**

manual drawing straight in the coordinate system

Target of slope + intercept or 2 points

Calculation of intersection, intersection angles, axle breakdown

Representation of parabolas with X / Y symmetry and form Y = ax² + bx + c