How do I create a logarithmic scale graph and determine line spacing?

In summary, when creating a graph using logarithmic scale, the dimensions of the graph should also be logarithmized if the units being used already have logarithm built in. If not, the graph will have evenly spaced divisions representing the units. Otherwise, a logarithmic graph will have lines at regular intervals, with the spacing between lines being proportional to the log of the value represented. If logarithmic graph paper is not available, an approximation can be made using sets of three regularly spaced lines.
  • #1
Leonardo Machado
57
2
Hello every one.

Today's question is: if I'm writte a graph using logarithm scale, must i use the dimensions of the graph "logarithmized" too ?

i.e : A Distance x Force graph must have its dimensions as log (m) x log (N) ? or it is just valid for the module ?

Thanks for the tips
 
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  • #2
If the units you are using already have the logarithm build it (ex, dB), then your graph will have evenly spaced divisions representing those units. For example, you may have a division after every 0.5 dB and every unit dB labelled along the edge.

Otherwise, you would normally use a logarithmic graph where the lines spacing varies and repeats a pattern after every power of ten (assuming it's a base 10 log). So you might have lines at 10M, 20M, 50M, 100M, 200M, etc, and the spacing between the lines would be proportional to the log of the ratio of the values represented by those lines.

If you don't have logarithmic graph paper, you can get an approximate with sets of three regularly spaced line at 10, 20, 50, 100.

If that's not your question, try again.
 

1. What is a logarithmic scale graph?

A logarithmic scale graph is a type of graph where the scale of the x-axis or y-axis is not evenly spaced. Instead, the intervals between each tick mark increase by a constant multiplier. This allows for a better visualization and comparison of data that covers a wide range of values.

2. How do you read a logarithmic scale graph?

To read a logarithmic scale graph, you must first identify the base of the logarithm used. This is usually indicated next to the axis label. Then, each tick mark on the axis represents a value that is a power of the base. For example, on a log base 10 scale, each tick mark represents a value that is 10 times greater than the previous tick mark. To interpret the data, you must use the tick marks to determine the approximate value of the data point.

3. What are the advantages of using a logarithmic scale graph?

Logarithmic scale graphs have several advantages, including the ability to display a wide range of data in a single graph, making it easier to compare trends and patterns. They also help to reduce the visual impact of outliers, making it easier to focus on the main data points. Additionally, logarithmic scales are useful for representing data that follows exponential or power-law relationships, as these can be visualized as straight lines on a log scale.

4. When should you use a logarithmic scale graph?

A logarithmic scale graph is useful when the data being plotted covers a large range of values, making it difficult to interpret on a linear scale. This is often the case with scientific data, such as measurements of earthquake magnitude, population growth, or pH levels. Logarithmic scales can also be used when analyzing data that follows exponential or power-law relationships.

5. Can a logarithmic scale graph be used for negative values?

Yes, a logarithmic scale graph can be used for negative values. However, the logarithm of a negative number does not exist, so the values on the logarithmic scale must be offset by a constant value to avoid taking the logarithm of a negative number. This is usually indicated by a vertical dashed line on the graph. It is important to note that the data must still follow a logarithmic relationship, even if the values are negative, for a logarithmic scale graph to be appropriate.

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