Probabilistic latency modeling
Touchscreen testing techniques are described. In one or more implementations, a piece of conductor (e.g., metal) is positioned as proximal to a touchscreen device and the touchscreen device is tested by simulating a touch of a user. This technique may be utilized to perform a variety of different testing of a touchscreen device, such as to test latency and probabilistic latency. Additional techniques are also described including contact geometry testing techniques.
1. A method comprising:
displaying a moving item by a touchscreen device;
receiving data that describes one or more touch inputs that are to follow the display of the moving item; and
calculating end-to-end latency of the computing device based on the data corresponding to the one or more touch inputs and data describing the display of the moving item by at least computing a distance between a position at which the item is displayed and a position at which the touch input is received at a particular point in time, wherein the calculating involves the following expression to model the end-to-end latency: end-to-end latency=d/v, where d is distance and v is average velocity.
2. A method as described in claim 1 , wherein the data describes one or more touch inputs received through detecting a part of a user's body by the touchscreen device.
3. A method as described in claim 1 , wherein the touchscreen device uses capacitive sensors.
4. A method as described in claim 1 , wherein the calculating compares velocity of the display of the moving item with velocity of the one or more touch inputs.
5. A method as described in claim 1 , wherein the calculating compares variance of the one or more touch inputs with the display of the moving item.
6. A method as described in claim 1 , wherein the calculating includes computing the distance between the position at which the item is displayed and the position at which the touch input is received at a plurality of different times.
7. A method as described in claim 1 , wherein the calculating includes analyzing the data to find a model that represents the data.
8. A computing device comprising:
a touchscreen; and
one or more modules implemented at least partially in hardware, the one or more modules configured to perform operations comprising:
displaying a moving item on the touchscreen;
receiving data that describes one or more touch inputs that are to follow the display of the moving item; and
calculating end-to-end latency of the computing device based on the data corresponding to the one or more touch inputs and data describing the display of the moving item by at least computing a distance between a position at which the item is displayed and a position at which the touch input is received at a particular point in time, wherein the calculating involves the following expression to model the end-to-end latency: end-to-end latency=d/v, where d is distance and v is average velocity.
9. A computing device as described in claim 8 , wherein the data describes one or more touch inputs received through detecting a part of a user's body by the touchscreen device.
10. A computing device as described in claim 8 , wherein the touchscreen uses capacitive sensors.
11. A computing device as described in claim 8 , wherein the calculating compares velocity of the display of the moving item with velocity of the one or more touch inputs.
12. A computing device as described in claim 8 , wherein the calculating compares variance of the one or more touch inputs with the display of the moving item.
13. A computing device as described in claim 8 , wherein the calculating includes computing the distance between the position at which the item is displayed and the position at which the touch input is received at a plurality of different times.
14. A computing device as described in claim 8 , wherein the calculating includes analyzing the data to find a model that represents the data.
15. A method comprising:
displaying an item by a touchscreen device;
recording data that describes the displaying;
receiving one or more touch inputs on the touchscreen device;
recording data that describes the one or more touch inputs; and
calculating end-to-end latency of the touchscreen device based on the data that describes the displaying and the data that describes the one or more touch inputs by at least computing a distance between a position at which the item is displayed and a position at which the touch input is received at a particular point in time, wherein the calculating involves the following expression to model the end-to-end latency: end-to-end latency=d/v, where d is distance and v is average velocity.
16. A method as described in claim 15 , wherein the touchscreen device uses capacitive sensors.
17. A method as described in claim 15 , wherein the item is a moving item and the calculating compares velocity of the display of the moving item with velocity of the one or more touch inputs.
18. A method as described in claim 15 , wherein the calculating compares variance of the one or more touch inputs with the display of the item at a plurality of different times.