Quicktime Movie

Filename: ffes.mov

A movie captured in real time of the system being used, with a commentary on what is happening. To play it, a Quicktime capable movie player is necessary.

The movie shows the features of the system, including:

• pen based input.
• automatic stroke grouping and symbol annotation.
• arbitrary symbol entry order.
• stroke regrouping with the "squiggle select".
• character recognition correction with a pop-up menu.
• selecting and moving parts of formulae.
• parsing of formulae, and the generation of a LaTeX preview.

The movie shows a user entering three formulae to demonstrate these features. In the first example, the user initially enters the formula x² + 4 and allows the system to recognise the symbols entered. The user then changes the formula to an integral, making it $\int x^2 + 4\ dx$. The user then generates the L^ATEX for this formula, and the preview is generated.

The second example shows the correction of recognition errors that the system makes. The user enters the formula x² + y² = z², but the system groups the strokes incorrectly, taking the y² as a single symbol, and the two strokes of the = as separate symbols. The user is able to fix this by going into modify stroke groups mode and drawing a line through the strokes that should belong to a single symbol. A stroke through the y splits it off from the 2 and a stroke through the two bars of the = combine them together. At this point, the y is still misrecognised, so the user enters modify characters mode. Clicking on the misrecognised y offers a list of alternatives provided by the character recogniser. If the correct symbol is on this list, the user is able to select it. Otherwise, they choose the Enter... option which allows them to enter from the keyboard what the symbol actually is. With the formula correctly entered and recognised, the user is able to generate the L^ATEX command string for it.

The system allows basic editing of formulae: moving and deletion of single or multiple symbols. This allows major structural rearrangement of formula once entered. In the third example, the user enters $\int x^2 + 4\ dx$ then, after generating the L^ATEX for it, decides that they want the integrand to be a fraction. Entering select and move mode allows the user to select the old integrand of x² + 4 and move it up so that the formula can be edited to make it $\int \frac{x^2 + 4}{\sqrt{x}}dx$. The user then decides that they want limits on the integral, so they again use select and move mode to make room between the integral sign and the integrand. After adding the limits, the final formula $\int^4_0 \frac{x^2 + 4}{\sqrt{x}}dx$ is complete, and the user again generates the L^ATEX for it.