CanoScan LiDE 30 Scanner

In a bid to digitize all the bills, documents, forms and papers lying around, I decided to buy a scanner. I wanted a simple, cheap flatbed scanner. But, the market seems to be full of expensive high resolution flatbed scanners or the printer-scanner-copier combo units that are too big and useless for me. So, taking the advise of a friend I bought a used CanoScan LiDE 30 flatbed scanner from the VR-Zone forums.

This scanner seems to be in good condition, though it looks a bit worn down. I downloaded and installed the drivers and the CanoScan Toolbox software. The scanner worked without any hitches with my Windows XP laptop. The scanner head moves a bit slow though. One advantage of this model that I noticed is that it draws power from its USB cable, so it does not even use an extra power cord. One less hassle! :-)

Picasaweb: Keyboard Shortcuts

Keyboard shortcuts are useful for browsing through the hundreds of photos friends share in their Picasaweb albums. Picasaweb seems to be sorely neglected by Google when it comes to keyboard shortcuts. One can only move to the previous or next photo. Shortcuts to zoom in/out and pan on a photo would have been useful.

  • Next photo: Right arrow key / j / n
  • Previous photo: Left arrow key / k / p

I find the easiest to use are the left/right arrow keys to flick through the photos.

LaTeX: Longtable

Tables are commonly created in LaTeX using the tabular environment. For example, a simple 2 column table:

\begin{tabular}{c c}
Tea & Coffee\\
Coke & Pepsi\\

These tables are treated as unbreakable by LaTeX. Thus, a long table will not be broken across a page break, but will be moved into the next page. If you want a table to flow across pages, by being broken across page breaks, the longtable package can be used to achieve that.

Load the longtable package:


Replace tabular with longtable:

\begin{longtable}{c c}
Tea & Coffee\\
Coke & Pepsi\\

Horizontal Spacing in LaTeX

LaTeX does spacing nicely most of the time. But, sometimes it becomes necessary to insert a little bit more of horizontal spacing. This might be between words of text, between math formulas or even between figures placed horizontally beside each other.

The following 3 TeX horizontal spacing macros can be used for this purpose:

  1. \enskip: Inserts 0.5 em of horizontal space.
  2. \quad: Inserts 1.0 em of horizontal space.
  3. \qquad: Inserts 2.0 em of horizontal space.

Inside TeX, the above are defined as:

  1. \def\enskip{\hskip.5em\relax}
  2. \def\quad{\hskip1em\relax}
  3. \def\qquad{\hskip2em\relax}

Note that em is a horizontal measurement unit and its value is dependent on the font being used. That is, it is a measurement unit that ships with a font. It is typically the width of the letter M of the font.

Reference: Pages 60 and 352 of The TeXBook by Donald E. Knuth

Robocopy: ERROR 5 (0x00000005)

I have faced this Robocopy error many times:

2010/03/20 11:48:37 ERROR 5 (0x00000005) Copying File C:\Foobar.pdf
Access is denied.
Waiting 30 seconds...

The reasons for this error are many and the fixes depends on the reasons:

  1. Check if the destination disk is full.
  2. Try the /COPY:DT option. By default, Robocopy copies using the option /COPY:DAT. This copies the Data, Attributes and Timestamps. /COPY:DT ignores the Attributes.

Sub-figures using subfloat in LaTeX

Two subfigures in a figure in LaTeX

To include more than one figures inside a figure the subfig package can be used. It provides the subfloat command that is used to specify each of the sub-figures as a figure. Its usage is shown below in a simple example:

Note that each of the subfigures can be given an optional label which can be used to refer to them in the text of the document.

If you are using TeX Live, in Ubuntu for example, subfig can be found in the texlive-latex-recommended package. Note that I have seen that subfig has problems working with Beamer.