In the third film of the Harry Potter series, the style of the Hogwarts school scarves changed from a solid striped pattern, to one featuring sets of trapped bar patterns. These scarves are long and full scarves (actors in the film often wind them several times around their necks). Atypically Knit used to have a pattern that very closely follows the movie style of the scarves, as well as give yarn, needle and color suggestions for the four house colors. See the link below for the full pattern.
The Atypically Knit pattern was designed before the third film actually was released (based off of teaser photos of the film), and after the fourth movie was released, some more close-up shots of the new style of scarf could be ascertained.With some color modification and contrast adjustment, it's possible to count the rows between the trapped bar pairs, and find that there are 8 stitches there. The bars themselves are clearly 4 rows long as well. Again modifying the contrast of the image, by best guess, there's 35 stitches between the trapped bar sets.
The Atypically Knit pattern calls for 27 rows of solid color between the trapped bar sets, then 3 for the bar color, 5 for the space between the bars, and then 3 more for the second bar. From the enhanced images, these numbers change to 35, 4, 8, and 4 rows, respectively. This is roughly a 33% increase for each section. So, the Atypically Knit pattern is in the correct proportions, but isn't quite dense enough to be a true movie representation. So, to modify the pattern to be a literal representation of the movie scarves, knit the scarf using one size smaller needles than called for (US6 for Nature Spun, US7 for Encore, or US8 for Utopia), cast on 120 stitches to knit in the round (another ~33% increase to keep the width of the scarf in proportion), and use the 35, 4, 8, 4 row count to complete the pattern.