# DEW1

DEW1 draws the solution of differential equation of first order with initial values t0 and y0. Program also draws the direction field.

## Drawing (*Initial values*)

Solution is drawn with initial values t0 and y0. Values can be written to **t=** and **y=** textfields and clicking the **Draw** -button. Or values can be pointed with a mouse.

## Equation

Differential equation may be selected from the pre-defined examples or may by defined by user. For example equation:

*y'* - 3**y* + 2**t* = 0

is first solved for *y'*:

*y'* = 3**y* - 2**t*,

then the right side of equation is given to the program:

3**y* - 2**t*.

Finally click the **Read equation** -button.

## Changing the scale (*Scale*)

The scale can be adjusted by chancing the values of **tmin**, **tmax**, **ymin** and **ymax** and clicking the **Change scale** -button.

## Numerical method (*General*)

The solution may be plotted by using one of the following algoritms: adaptive Runge-Kutta, Euler, improved Euler, Runge-Kutta or Adams-Bashforth.

For non-adaptive methods the stepsize may be adjusted via the **Stepsize** -textfield.

## Clearing (*General*)

**Clear** -button clears everything that has been drawn.